Vitamina D – Effetti collaterali, dosaggio, interazioni


D: Ho una prescrizione per la vitamina D 500000 UI, che dovrei prendere una volta alla settimana. Ho accidentalmente preso uno due giorni di fila. Cosa dovrei fare? Dovrei essere preoccupato?

A: Le persone spesso prendono accidentalmente i loro farmaci troppo frequentemente (o non abbastanza frequentemente). Ogni volta che ciò accade, è importante contattare il proprio medico curante per comprendere appieno la propria condizione. Le dosi di vitamina D variano a seconda della condizione che viene trattata. Quantità eccessive di vitamina D possono causare sintomi non specifici come nausea, vomito, scarso appetito, costipazione, debolezza e perdita di peso. Più seriamente, può anche aumentare i livelli ematici di calcio, causando confusione e anomalie del ritmo cardiaco. Michelle McDermott, PharmD

D: Come dovrebbe essere una capsula o una compressa di vitamina D da 50.000 unità?

A: La vitamina D2 o ergocalciferolo (Calciferol, Drisdol) è disponibile in capsule da 50.000 UI (unità internazionali) e in iniezione da 500.000 UI. Si prega di consultare il seguente link per un'immagine di una capsula di ergocalciferolo da 50.000 UI e ulteriori informazioni sulla vitamina D:

D: Quanta vitamina D è troppo da assumere?

A: La necessità di integratori vitaminici diversi per ogni individuo. Dipende da una varietà di fattori, tra cui dieta, stile di vita, storia medica e di prescrizione medica e fattori di rischio individuali. È sempre importante consultare il medico prima di assumere vitamine, integratori o prodotti da banco. Per ulteriori informazioni sulla vitamina D, visitare il nostro sito Web all'indirizzo. Beth Isaac, PharmD

D: È meglio assumere 1000 mg di vitamina C con 1000 UI di vitamina D? Cosa è raccomandato per gli anziani?

A: È sempre meglio assumere la tua fonte di vitamine attraverso la dieta, ma se ciò non è possibile, si consigliano integratori. Per la vitamina C, la quantità non aumenta per gli anziani. Ci sono stati diversi dosaggi raccomandati da vari enti governativi: la Food Standards Agency del Regno Unito consiglia 75 mg al giorno, la World Health Association raccomanda 45 mg al giorno, Health Canada 90 mg al giorno per i maschi e 7 5 mg al giorno per le femmine, e la National Academy of Sciences degli Stati Uniti raccomanda da 60 a 95 mg al giorno. La dose di assunzione superiore tollerabile è di 2.000 mg al giorno. La vitamina C è solubile in acqua, quindi ciò che non viene assorbito lascia il corpo nelle urine. Tuttavia, dosi molto elevate possono causare diarrea e una persona può ancora prendere troppo e causare danni al corpo. Per quanto riguarda la vitamina D, è liposolubile e una persona può sicuramente prendere troppo e causare danni al corpo. È stato somministrato in casi speciali di carenza per importi di 50.000 UI, ma l'attuale indennità giornaliera raccomandata dagli Stati Uniti è di 400 UI. Alcuni studi dimostrano che livelli più alti non vanno a beneficio degli anziani, mentre altri mostrano che 400 UI non sono sufficienti, quindi sono in corso ulteriori studi per scoprire quanto dovremmo davvero prendere. Nel frattempo, se sei in grado di uscire al sole, puoi anche beneficiare della vitamina D che il corpo ne assorbe. Patti Brown, PharmD

D: Quanti milligrammi di vitamina D al giorno sono effettivamente necessari?

A: L'attuale indennità giornaliera raccomandata dagli Stati Uniti per la vitamina D è la seguente: dalla nascita all'età di 50: 200 UI (unità internazionali) al giorno (le nuove linee guida in uscita raccomandano presto 400 UI al giorno). Età 51 a 70: 400 UI al giorno. A partire da 71 anni: 600 UI al giorno.

D: Il mio medico mi ha detto di assumere vitamina D per due mesi. Ma ho sentito parlare di alcuni effetti collaterali spaventosi. Una volta ho avuto una brutta reazione a un antidolorifico e ora sto attento con le medicine. Quanta vitamina D è sicura da assumere?

A: La vitamina D può essere assunta per una varietà di condizioni mediche, tra cui carenza di vitamina D, ipoparatiroidismo e osteoporosi. Il fornitore di assistenza sanitaria dovrebbe essere in grado di determinare meglio la dose specifica. È possibile avere troppa vitamina D e i sintomi da sovradosaggio possono includere mal di testa, debolezza, sonnolenza, secchezza delle fauci, nausea, vomito, costipazione, dolore muscolare o osseo, gusto metallico in bocca, perdita di peso, prurito della pelle, alterazioni del cuore tasso, perdita di interesse per il sesso, confusione, pensieri o comportamenti insoliti, sensazione di insolitamente caldo, forte dolore nella parte superiore dello stomaco che si diffonde alla schiena o svenimento. Un sovradosaggio di vitamina D può causare effetti collaterali gravi o potenzialmente letali e in tali casi è necessario consultare un medico di emergenza. Puoi anche trovare informazioni utili su. Sarah Lewis, PharmD

D: Quanta vitamina D è necessaria, per una donna, dopo i 65 anni?

A: La vitamina D è utile per l'assorbimento del calcio, la normale crescita e rimodellamento osseo, la funzione neuromuscolare e immunitaria e la riduzione dell'infiammazione. La RDA, o dose giornaliera raccomandata, di vitamina D negli adulti sani di età compresa tra 50 e 70 anni è di 400 UI al giorno. Le persone dovrebbero essere consapevoli del fatto che alcune fonti alimentari contribuiscono alla loro assunzione di vitamina D, e questo include pesce, latte, yogurt, uova e formaggio. Non dovresti assumere più di 400 UI al giorno o la quantità che potresti ottenere da un prodotto di calcio con vitamina D, se non diversamente indicato dal tuo medico. Ecco un link ad alcune informazioni sulla vitamina D che potresti trovare utili:

D: Il mio ginecologo mi ha appena somministrato 50.000 UI di vitamina D una volta alla settimana per 8 settimane. Ha detto che il mio livello di vitamina D era nel "gabinetto". È una dose sicura?

A: I pazienti spesso chiedono un'adeguata integrazione vitaminica. 50.000 UI sono la dose prescritta di vitamina D. Secondo la Food and Drug Administration (FDA) degli Stati Uniti, questa è una dose approvata per il trattamento di determinate condizioni. L'integrazione con vitamina D è estremamente specifica per il paziente e dipende da vari fattori tra cui dieta, storia medica e di prescrizione medica e fattori di rischio individuali. È importante che il medico esegua un monitoraggio di routine durante il trattamento con vitamina D. Per ulteriori informazioni sulla vitamina D:

D: Quali sono i benefici della vitamina D3?

A: La vitamina D ha molte funzioni nel corpo, tra cui la promozione dell'assorbimento del calcio, la crescita e il rimodellamento osseo, la riduzione dell'infiammazione, nonché la crescita e la rigenerazione delle cellule. Ci sono stati molti dibattiti e studi sul beneficio della vitamina D3 rispetto alla vitamina D2, ma non esiste una risposta definitiva a questa domanda. È stato scoperto negli studi che la vitamina D3 e D2 sono ugualmente efficaci. Per maggiori informazioni sulla vitamina D:

D: Qual è l'indennità giornaliera totale raccomandata di vitamina D?

A: Ad oggi, non è stata ancora stabilita un'indennità giornaliera raccomandata (RDA) per la vitamina D, a causa di prove cliniche insufficienti. Esiste invece un numero di assunzione adeguata (AI) per la vitamina D. L'intelligenza artificiale è definita come un livello di assunzione sufficiente per mantenere livelli ematici sani di una forma attiva di vitamina D. Attualmente, l'assunzione adeguata per una donna di 40 anni è di 5 microgrammi (mcg) o 200 unità internazionali (UI) al giorno. Affinché la vitamina D funzioni, devi anche assicurarti di assumere abbastanza calcio ogni giorno. È sempre una buona idea verificare con il proprio medico in questioni come questa. Consultare il proprio fornitore di assistenza sanitaria per assistenza nel proprio caso specifico. Troverai informazioni complete sui due tipi di vitamina D disponibili in commercio in queste due pagine Web: e Gregory Latham, RPh

D: Sto assumendo 50 unità di vitamina D. Dovrei assumere altre vitamine con esso?

A: Un multivitaminico quotidiano è sempre una buona scelta per integrare la dieta, soprattutto se non viene consumata una dieta equilibrata. Inoltre la maggior parte delle donne ha bisogno di ulteriore calcio nella propria dieta. L'assunzione giornaliera raccomandata per le donne oltre i 50 anni è di 1200 mg al giorno. Esistono due forme principali di calcio: citrato e carbonato. Il carbonato di calcio è ben assorbito e di solito meno costoso. È assorbito meglio con il cibo. Il citrato di calcio è ottimo per le persone con acido dello stomaco basso. Il calcio può causare alcuni effetti collaterali come gas, gonfiore e costipazione. La quantità di calcio elementare assorbita dipende dalla quantità di calcio consumata. Di solito dosi

D: Quanta vitamina D dovrei prendere? Sono un maschio di 67 anni.

A: La quantità di vitamina D da assumere può variare in base ai livelli ematici. Dovresti chiedere al tuo medico se dovresti assumere un integratore di vitamina D da banco o se devi essere sottoposto a prescrizione medica. Questo può essere determinato con un test di laboratorio. Per ulteriori informazioni, puoi visitare Gerald Levy, RPh

D: Mi è stato detto di assumere 2000 UI di vitamina D al giorno per le ossa deboli. La vitamina D3 è la stessa?

A: La vitamina D è un termine generale per la combinazione di vitamina D2 (ergocalciferolo) e vitamina D3 (colecalciferolo). La vitamina D e D3 sono spesso usate in modo intercambiabile. Una volta ingerita, la vitamina D passa attraverso una serie di passaggi che alla fine aiutano i livelli di calcio e la formazione ossea. Il nostro sito Web contiene un buon articolo che può essere utile: con qualsiasi nuovo farmaco, tenere presente che può verificarsi l'interazione tra i farmaci. Se stai attualmente assumendo farmaci, consulta il tuo farmacista o medico prima di aggiungere vitamina D ai tuoi farmaci. Jeff O'Connell, PharmD

Q: Sono una donna attiva di 45 anni. Sono alto 5 piedi e peso 105 libbre. Ho iniziato a prendere 1.000 milligrammi di vitamina D al giorno. È troppo? In tal caso, qual è la giusta quantità?

A: La vitamina D ha ricevuto molta attenzione da parte dei media ultimamente. La vitamina D aiuta l'organismo ad assorbire il calcio e crescere ossa sane, e riduce l'infiammazione. La ricerca attuale ha dimostrato che la vitamina D è anche coinvolta nella crescita e differenziazione cellulare, morte cellulare e generazione di vasi sanguigni. La difficoltà con la vitamina D è che è naturalmente presente in pochissimi alimenti. Le migliori fonti sono i pesci grassi, tra cui salmone, tonno e sgombro. Gli alimenti fortificati, come il latte, forniscono la maggior parte della vitamina D nelle diete americane. La vitamina D viene prodotta nei nostri corpi quando la nostra pelle è esposta ai raggi ultravioletti del sole. Le persone possono diventare carenti di vitamina D se non consumano abbastanza dal cibo o se la loro esposizione alla luce solare è limitata o inefficace a causa della protezione solare. Il tuo medico può determinare se sei carente di un semplice esame del sangue e può quindi suggerire un supplemento appropriato. Per ulteriori informazioni sulla vitamina D, visitare. Michelle McDermott, PharmD

D: Mia moglie ed io stiamo assumendo multivitaminici ad alte prestazioni, che hanno 400 unità internazionali di vitamina D, al mattino e un ulteriore gel soft vitamin D-3 (2.000 UI) la sera. Abbiamo 68 e 69 anni. Va bene o troppa vitamina D? Entrambe le pillole sono del marchio Kirkland della farmacia Costco.

A: L'attuale dose giornaliera raccomandata per le età da 51 a 70 è di 400 unità internazionali al giorno con una dose massima giornaliera di 2.000 UI al giorno. Questa dose include la vitamina D che assumi da tutte le fonti, come cibo e luce solare. L'assunzione di troppa vitamina D può causare spiacevoli effetti collaterali, come nausea, vomito, costipazione e perdita di appetito. La quantità di vitamina D che stai ricevendo dal tuo attuale trattamento è leggermente superiore al massimo giornaliero raccomandato. Tieni presente che questo è solo un importo raccomandato e che ogni persona è diversa e richiede importi diversi. Probabilmente è meglio per te e tua moglie parlare con il medico per determinare quanta vitamina D è raccomandata per te.

D: Quanto è importante la vitamina D e cosa fa?

A: Le persone assumono vitamina D per molte ragioni che hanno alcune prove a sostegno, ma non prove sufficienti per dire scientificamente che è benefico. La vitamina D è importante, tuttavia, perché i nostri corpi ne hanno bisogno per assorbire il calcio. I nostri corpi producono vitamina D quando siamo esposti alla luce solare. Sono sufficienti solo 15-30 minuti al giorno di luce solare diretta. Ma con la promozione di creme solari e avvertenze sul cancro della pelle, molte persone non ricevono la luce solare di cui hanno bisogno. Pertanto, un supplemento di vitamina D è necessario per alcune persone.

D: Prendo la vitamina D su prescrizione. Quale vitamina D dal negozio posso prendere che è equivalente?

A: Esistono due diverse forme di vitamina D: D2 (ergocalciferolo) e D3 (colecalciferolo). La vitamina D con obbligo di prescrizione medica è ergocalciferolo (Drisdol) ed è disponibile in una dose di 50.000 unità internazionali (UI), che di solito viene assunta una volta alla settimana. La maggior parte di ciò che è disponibile al banco è il colecalciferolo, che viene somministrato in dosi più basse, 400 o 1.000 UI, che devono essere assunte una volta al giorno. I pazienti con una carenza di vitamina D di solito fanno meglio con la dose di 50.000 UI per diversi mesi fino a quando i livelli tornano alla normalità. Quindi, può essere possibile essere posto su una dose da banco più bassa ogni giorno per mantenere i livelli. Il medico sarà in grado di dirti quale dose di vitamina D è la migliore per te, in base ai tuoi livelli ematici. Per ulteriori informazioni sulle due formulazioni di vitamina D, consultare i seguenti collegamenti quotidiani sulla salute: e. Laura Cable, PharmD

D: Ho diagnosticato un deficit di vitamina D e calcio, dopo essere stato inizialmente trattato per l'osteoporosi. Le unghie e la pelle della cuticola precedentemente desquamata sono migliorate da quando ho aumentato la mia vitamina D. Qualche relazione? Zyrtec, Benadryl o Sudafed influiscono sull'assorbimento di vitamina D o calcio? Ho delle gravi allergie e prendo alcuni antistaminici tutto l'anno.

A: La forza delle tue unghie probabilmente è correlata alla vitamina D ma in realtà è più correlata al calcio. La vitamina D da sola non ha alcun effetto sulla forza dell'unghia; il calcio ha un effetto su capelli, pelle e unghie. Ma il calcio ha bisogno della vitamina D per essere utilizzato e assorbito correttamente dall'organismo. Quindi, se hai avuto una carenza di vitamina D, probabilmente non stavi usando il tuo calcio in modo adeguato. L'assunzione di Zyrtec (cetirizina), Benadryl (ciphenhydramine) o Sudafed (pseudoefedrina) non dovrebbe influire sull'assorbimento di vitamina D o calcio, quindi è ancora possibile tenere sotto controllo le allergie e avere unghie più belle!

Q: Prendo Caltrate 600 + D. Contiene 400 unità internazionali di vitamina D. Il mio multivitaminico ha anche 400 UI di vitamina D. Ho letto che si consigliano 1.200 UI di vitamina D. Devo prendere un supplemento per compensare le altre 400 UI. Ci sono integratori che contengono solo 400 UI?

A: Sì, le versioni di vitamina D sono disponibili come 400 UI, da produttori come Nature Made e Finest Natural. L'assunzione giornaliera raccomandata effettiva per qualcuno della tua età è di 400 UI al giorno. Tuttavia, il medico dovrebbe essere in grado di dirti se è necessario assumere integratori di vitamina D aggiuntivi e quanto è salutare.

D: Quanta vitamina D dovrei prendere ogni giorno?

A: L'indennità giornaliera raccomandata di vitamina D è attualmente di 400 UI al giorno, anche se alcuni studi suggeriscono che dosi più elevate possono essere utili. Allo stesso tempo, una persona può assumere troppa vitamina D nel corpo. Non è solubile in acqua e la tossicità può accumularsi a dosi troppo elevate. Il modo migliore per ottenere vitamine è prima attraverso la dieta, ma se ciò non è possibile, un integratore può aiutare. L'Ufficio dei supplementi dietetici del National Institutes of Health (NIH) afferma che i seguenti alimenti contengono vitamina D: pesce grasso (pesce gatto, salmone, sgombro, sardine, tonno, anguilla), uova intere, fegato di manzo e oli di fegato di pesce. Prendiamo anche vitamina D dal sole e alcuni alimenti – come alcuni tipi di latte, yogurt e pane – ne sono arricchiti. Come con tutti i farmaci, è necessario consultare il proprio medico per vedere quale dose è la migliore per lei. Per ulteriori informazioni su dieta e nutrizione, visitare il nostro sito Web all'indirizzo. Patti Brown, PharmD

D: Di quanta vitamina D ha bisogno una donna di 62 anni e questo integratore causerebbe vampate di calore e sudorazioni notturne?

A: Generalmente, si raccomandano integratori di vitamina D e calcio per le donne di età superiore ai 60 anni per prevenire l'osteoporosi (perdita di massa ossea). Il corpo ha bisogno di vitamina D affinché il calcio funzioni efficacemente. La vitamina D viene talvolta utilizzata in altri trattamenti, come la prevenzione del cancro, della depressione o delle malattie cardiache. La tossicità da vitamina D è rara e una persona dovrebbe assumerne una quantità enorme per avere tossicità. I sintomi di tossicità sono nausea, vomito, anoressia, confusione, costipazione e perdita di peso. La vitamina D non provoca sudorazioni notturne o vampate di calore. Lori Mendoza, PharmD

D: Perché il mio livello di vitamina D dovrebbe continuare a scendere estremamente basso? Lavoro di notte e ho un'allergia al latte. Prendo integratori di vitamina D, ma devo prenderne molto ogni settimana.

A: Se stai lontano dal sole, soffri di allergie al latte o segui una dieta vegetariana rigorosa, sei a rischio di carenza di vitamina D. Conosciuta come la "vitamina del sole", la vitamina D viene prodotta dall'organismo in risposta alla luce solare. Si verifica anche in modo naturale negli alimenti tra cui pesce, oli di fegato di pesce, tuorli d'uovo e prodotti lattiero-caseari e cereali arricchiti. Molti fattori possono contribuire alla carenza di vitamina D oltre a non ricevere abbastanza luce solare: avere la pelle scura (il pigmento melanina riduce la capacità della pelle di produrre vitamina D in risposta all'esposizione alla luce solare; alcuni studi dimostrano che gli anziani con pelle più scura sono ad alto rischio di vitamina Carenza di D), reni che non sono in grado di convertire la vitamina D (con l'avanzare dell'età, i loro reni sono meno in grado di convertire la vitamina D nella sua forma attiva, aumentando così il rischio di carenza di vitamina D), alcuni problemi medici, tra cui la malattia di Crohn e la celiachia (questi influenzano la capacità dell'intestino di assorbire la vitamina D dal cibo), con un indice di massa corporea di 30 o superiore (tali persone spesso hanno bassi livelli ematici di vitamina D perché viene estratta dal sangue dalle cellule adipose, alterandone il rilascio nella circolazione ). Dovresti parlare con il tuo medico di un piano per mantenere i livelli di vitamina D più costanti nel tempo. Per ulteriori informazioni sulla vitamina D, visitare. Lori Mendoza, PharmD

D: Perché c'è vitamina D in quasi tutto. Mi è stata data una prescrizione e ho sentito dolore in ogni centimetro del mio corpo. Lo giuro, anche le mie ossa mi fanno persino male. Ho paura di prendere il calcio con vitamina D ora. Ho impiegato due settimane di potenti farmaci antidolorifici per liberarmi del dolore.

A: La prescrizione di vitamina D è una dose piuttosto grande e se non sei così carente di vitamina D, può causare alcuni effetti collaterali come dolore osseo, problemi muscolari, mal di occhi, gusto metallico e sete eccessiva. I prodotti da banco che contengono vitamina D di solito non hanno più della dose giornaliera raccomandata di 400 UI e i pazienti possono tollerare molto bene quel dosaggio. Puoi acquistare calcio senza vitamina D, ma tieni presente che il calcio ha bisogno di vitamina D per essere assorbito e utilizzato dalle ossa. Se vuoi evitare gli integratori, potresti essere in grado di assumere abbastanza vitamina D attraverso molte fonti alimentari come pesce, uova, latte arricchito e olio di fegato di merluzzo. La luce solare, anche solo 10 minuti, può contribuire alla produzione di vitamina D.

D: Ho assunto vitamina D per tutto l'inverno. Ora che sono più all'aperto e sono in grado di mostrare la mia pelle al sole, a quale dosaggio dovrei ridurre? O non ne ho bisogno? Può essere dannoso prenderne un po 'ogni giorno?

A: In bambini e adulti sani, la vitamina D a dosi fino a 2.000 UI (unità internazionali) è considerata sicura. Se assunto ad alte dosi, la vitamina D può causare nausea e vomito, confusione e gravi problemi cardiaci. La vitamina D prodotta nel corpo dal sole non raggiunge livelli pericolosi. La pelle produce vitamina D se esposta al sole diretto. Bastano da 5 a 30 minuti senza protezione solare alcune volte a settimana, a seconda della copertura nuvolosa. Ma quando esci al sole, dovresti indossare indumenti protettivi e utilizzare la protezione solare (con un SPF di 8 o più) per ridurre il rischio di cancro della pelle. Nei mesi invernali nella metà settentrionale degli Stati Uniti, il sole non è abbastanza forte per la pelle da produrre vitamina D. Consulta il tuo medico sulla migliore dose di vitamina D per te in tutte le stagioni, così come il quantità adeguata di esposizione al sole e uso della protezione solare. Kristen Dore, PharmD

Q: Ho 57 anni. Prendo un multivitaminico quotidiano, più un supplemento di calcio e vitamina C. Dovrei prendere anche la vitamina D separatamente?

A: Esistono sul mercato multivitaminici che contengono vitamina D. È anche utile mangiare cibi ricchi di vitamina D, come cereali fortificati e latte, o tonno in olio leggero. Gerald Levy, RPh

Q: Sono una femmina adulta. Va bene per me assumere quotidianamente vitamina D3?

A: La vitamina D è inclusa nella maggior parte dei multivitaminici, di solito in dosaggi da 50 UI a 1.000 UI. Per gli adulti di età inferiore ai 50 anni, si consigliano 200 UI al giorno. Per tutti gli individui dai 50 ai 70 anni, si consigliano 400 UI. Per coloro che hanno più di 70 anni, 600 UI sono la raccomandazione giornaliera. Il limite superiore raccomandato per la vitamina D è di 2.000 UI al giorno; le tossicità possono verificarsi quando viene assunto in dosi più elevate. Dovresti parlare con il tuo medico di quanta vitamina D dovresti assumere ogni giorno, poiché i fabbisogni vitaminici sono diversi per i diversi individui. Per ulteriori informazioni, visitare. Gerald Levy, RPh

D: Ho avuto gravi problemi di acne e peso da quando mi sono diplomato al liceo e ho appena scoperto di avere una carenza di vitamina D. Potrebbe essere questa la causa della mia acne e aumento di peso?

A: La vitamina D è una vitamina liposolubile che è naturalmente presente in pochissimi alimenti, aggiunta ad altri e disponibile come integratore alimentare. Viene anche prodotto endogeno quando i raggi ultravioletti della luce solare colpiscono la pelle e innescano la sintesi di vitamina D. La vitamina D è essenziale per promuovere l'assorbimento del calcio nell'intestino e mantenere adeguate concentrazioni sieriche di calcio e fosfato per consentire la normale mineralizzazione dell'osso e prevenire la tetania ipocalcemica. È anche necessario per la crescita ossea e il rimodellamento osseo da parte di osteoblasti e osteoclasti. Senza una quantità sufficiente di vitamina D, le ossa possono diventare sottili, fragili o deforme. La sufficienza di vitamina D previene il rachitismo nei bambini e l'osteomalacia negli adulti. Insieme al calcio, la vitamina D aiuta anche a proteggere gli anziani dall'osteoporosi. Negli integratori e negli alimenti arricchiti, la vitamina D è disponibile in due forme, D2 (ergocalciferolo) e D3 (colecalciferolo). La vitamina D2 è prodotta dall'irradiazione UV dell'ergosterolo nel lievito e la vitamina D3 è prodotta dall'irradiazione del 7-deidrocolcolesterolo dalla lanolina e dalla conversione chimica del colesterolo. La ricerca suggerisce che l'obesità è associata a carenza di vitamina D. La Food and Drug Administration statunitense non disciplina rigorosamente erbe e integratori. Non esiste alcuna garanzia di resistenza, purezza o sicurezza dei prodotti e gli effetti possono variare. In generale, gli integratori alimentari devono essere assunti solo sotto la supervisione del proprio medico. Per informazioni più specifiche, consultare il proprio medico o farmacista per una guida basata sulle proprie condizioni specifiche e sui farmaci attuali. Shereen A. Gharbia, PharmD

D: Attualmente sto assumendo 50.000 unità di vitamina D una volta alla settimana. Da quando lo prendo, mi fanno male le ginocchia e le gambe. È troppo Vitamim D?

A: Ergocalciferol o vitamina D2 è una forma di vitamina D disponibile in compresse o iniezioni di dosaggio. La vitamina D2 è usata per trattare una carenza di vitamina D, bassi livelli di fosfato, rachitismo, osteoporosi o ipoparatiroidismo. Una dose di prescrizione tipica di compresse di vitamina D2 è di 50.000 UI a settimana. Per alcune condizioni, è necessario solo per un breve periodo di tempo, ad esempio alcuni mesi. È possibile ottenere un sovradosaggio di vitamina D. Il medico può dire se si sta assumendo troppa vitamina D attraverso un esame del sangue. Secondo il manuale sui farmaci AHFS, un sovradosaggio di vitamina D può dare sintomi di dolore osseo e muscolare. Discutere i sintomi con il proprio medico e chiedere se è possibile controllare il livello di vitamina D. Per ulteriori informazioni sull'ergocalciferolo (vitamina D2), consultare il seguente link sulla salute quotidiana. Laura Cable, PharmD

D: Quanti milligrammi sono nel 2000 UI? Sono pillole di vitamina D3.

A: Le quantità di vitamina D negli integratori sono misurate in entrambi i microgrammi (non milligrammi) e unità internazionali. L'attività biologica di 1 microgrammo (mcg) è pari a 40 UI o per l'assunzione giornaliera raccomandata per gli adulti 400 UI è pari a 10 microgrammi. Pertanto, 2000 UI sarebbero pari a 50 microgrammi o 0,05 milligrammi. Per ulteriori informazioni, consultare il proprio fornitore di assistenza sanitaria. Michelle McDermott, PharmD

D: Ho iniziato a prendere la prescrizione di vitamina D e ho provato dolore in ogni centimetro del mio corpo. Mi facevano persino male le ossa. Ho paura di prendere il calcio con vitamina D ora. Ci sono voluti 2 settimane di antidolorifici ad alta potenza per sbarazzarsi del dolore. È stato terribile.

A: La prescrizione di vitamina D è una dose piuttosto grande e se non sei così carente di vitamina D, può causare alcuni effetti collaterali come dolore osseo, problemi muscolari, mal di occhi, gusto metallico e sete eccessiva. I prodotti da banco che contengono vitamina D di solito non hanno più della dose giornaliera raccomandata di 400 UI e i pazienti possono tollerare molto bene quel dosaggio. Puoi acquistare il calcio da solo senza vitamina D se davvero non vuoi assumere vitamina D, ma tieni presente che il calcio ha bisogno della vitamina D per essere assorbito e utilizzato dalle ossa. Se sei totalmente contrario a qualsiasi integratore di vitamina D, potresti essere in grado di assumere abbastanza vitamina D attraverso molte fonti alimentari come pesce, uova, latte arricchito e olio di fegato di merluzzo. La luce solare, anche solo 10 minuti, può contribuire alla produzione di vitamina D. Lori, PharmD

D: I miei test di laboratorio dimostrano che sono carente di vitamina D. Il mio medico ha prescritto vitamina D3 5000 UI. Ci sono effetti collaterali che sono probabili?

A: Il colecalciferolo è la vitamina D3. La vitamina D è importante per l'assorbimento del calcio dallo stomaco e per il funzionamento del calcio nel corpo. Il colecalciferolo è usato per trattare o prevenire molte condizioni causate da una mancanza di vitamina D, in particolare le condizioni della pelle o delle ossa. Gli effetti collaterali della vitamina D3 sono principalmente legati all'assunzione di troppa vitamina. Interrompere l'assunzione di colecalciferolo e chiamare immediatamente il medico se si verificano gravi effetti collaterali come: problemi di pensiero, cambiamenti nel comportamento, sensazione di irritabilità; urinare più del solito; dolore al petto, respiro corto; o primi segni di sovradosaggio di vitamina D (debolezza, gusto metallico in bocca, perdita di peso, dolore muscolare o osseo, costipazione, nausea e vomito). Puoi anche trovare informazioni utili su. Sarah McKenney Lewis, PharmD

D: Attualmente prendo 1.000 mg di vitamina D3 per bassi livelli di vitamina D. È abbastanza? Ho sentito che gli uomini sopra i 55 anni hanno bisogno di zinco extra. Qual è la quantità consigliata?

A: Le raccomandazioni dell'Institute of Medicine per l'assunzione di vitamina D per le persone di età compresa tra 51 e 70 anni sono 400 unità internazionali = 10 mcg = 0,01 mg. Nella tua domanda, dichiari di assumere 1000mg. Puoi indicare 1000 mcg (microgrammi anziché milligrammi). I punti decimali e micro vs. milli fanno una differenza enorme. In entrambi i casi, stai chiaramente prendendo più di quanto raccomandato dall'Institute of Medicine. Queste raccomandazioni sono state formulate nel 1997 e alcuni esperti ritengono che queste linee guida debbano essere riviste e probabilmente aumentate. Per quanto riguarda lo zinco, l'indennità dietetica raccomandata dagli Stati Uniti (RDA) è di 11 mg / giorno per gli uomini. La supplementazione probabilmente non deve superare i 20 mg / die nelle persone sane. Gli studi hanno dimostrato che gli uomini più anziani sono a maggior rischio di carenza di zinco. Tuttavia, troppo zinco può essere dannoso. L'eccessivo assorbimento di zinco sopprime l'assorbimento di rame e ferro. Ciò può comportare cose come complicanze urinarie. L'opzione migliore per una vita sana è una dieta ed esercizio fisico adeguati. Lowell Sterler, RPh

D: Prendo la vitamina D 50000 prescritta una volta alla settimana. Devo continuare a prendere anche la mia dose giornaliera?

A: Poiché il tuo operatore sanitario conosce meglio la tua situazione medica, è importante consultare lui / lei per determinare la dose di vitamina D appropriata per te. Questa informazione è solo educativa. È importante consultare il proprio medico o operatore sanitario per qualsiasi domanda specifica relativa alle proprie condizioni mediche o ai farmaci; in particolare prima di intraprendere qualsiasi azione. Derek Dore, PharmD

D: Ho 58 anni, lavoro alla scrivania per tutta la settimana e non esco molto al sole durante la settimana. I rapporti differiscono su molta vitamina D che dovremmo prendere. Che cosa mi consiglia?

A: Le raccomandazioni dell'Institute of Medicine per l'assunzione di vitamina D per le persone di età compresa tra 51 e 70 anni sono 400 unità internazionali = 10 mcg = 0,01 mg. Queste raccomandazioni sono state fatte nel 1997 e alcuni esperti ritengono che queste linee guida debbano essere rivisitate e possibilmente ampliate. La dose riflette l'assunzione di vitamina D per tutte le fonti. Una corretta dieta ed esercizio fisico sono importanti anche per mantenere una buona salute, soprattutto se si ha un lavoro che è principalmente fermo tutto il giorno.

D: Quali sono alcuni dei sintomi della carenza di vitamina D?

A: I sintomi della carenza di vitamina D possono variare tra gli individui, a seconda della presenza di eventuali complicanze, come la frattura ossea, la gravità della carenza di vitamina D e altri fattori. Molte persone non hanno sintomi di carenza di vitamina D fino a quando non sono presenti complicanze. I sintomi possono anche essere lievi. I sintomi della carenza di vitamina D comprendono dolore posturale, postura curva, crampi muscolari, debolezza e formicolio e perdita di altezza. Avere la pelle molto pallida può indicare che una persona è a rischio di carenza di vitamina D, nonché per altri disturbi, malattie e condizioni. Le complicanze della carenza di vitamina D possono includere rachitismo, osteomalacia e osteoporosi. I sintomi di queste complicanze comprendono deformità ossee e fratture ossee. Esistono altre possibili complicanze o malattie che possono avere un legame con la carenza di vitamina D. Questi includono ipertensione, depressione, sclerosi multipla, artrite, malattie cardiovascolari del diabete di tipo 2 e un aumentato rischio di cancro. Le prime indicazioni di carenza di vitamina D sono sudorazione abbondante, irrequietezza e irritabilità. La carenza cronica induce numerose malformazioni ossee dovute all'ammorbidimento delle ossa: bowlegs, knock-ginocchio, rosario rachitico (bordatura delle estremità delle costole), ingrossamento di polsi e caviglie, petto di piccione, chiusura ritardata delle fontanelle, ammorbidimento del cranio e rigonfiamento della fronte. Se non trascorri molto tempo al sole o stai sempre attento a coprire la pelle (protezione solare) inibisce la produzione di vitamina D), dovresti parlare con il tuo medico dell'assunzione di un integratore di vitamina D. Gli alimenti contenenti vitamina D sono: uova, olio di fegato di merluzzo, salmone, sgombro, tonno sott'olio, formaggio svizzero, cereali fortificati pronti da mangiare con vitamina D. Se hai qualche dubbio, contatta il tuo medico di cui parlane con in particolare se si hanno fattori di rischio per la carenza di vitamina D. Gerry, RPh

D: Ho 70 anni e sono preoccupato per la mia assunzione di vitamina D. Quanta vitamina D dovrebbe assumere un 70enne?

A: Le raccomandazioni dell'Istituto di medicina per la vitamina D per le persone di età compresa tra 51 e 70 anni sono 400 unità internazionali. Queste raccomandazioni sono state formulate nel 1997 e alcuni esperti ritengono che queste linee guida debbano essere rivisitate e possibilmente ampliate. Altri elementi importanti per una vita sana sono la dieta e l'esercizio fisico adeguati. Potresti voler controllare il seguente riferimento per ulteriori informazioni:.

D: La mia lettura di vitamina D era di 19 anni e il mio medico ha prescritto una dose di 50.000 unità per 3 mesi e successivamente 1.000 al giorno. È normale?

A: Secondo la letteratura medica, la carenza di vitamina D è definita come un livello di 25OHD inferiore a 20 ng / mL. Il regime suggerito per i pazienti con carenza di vitamina D è di 50.000 unità di vitamina D una volta alla settimana per 2-3 mesi, seguite da 800-1000 unità al giorno in seguito. Questa informazione è solo educativa.

Q: Is 2700 IU of vitamin D too much to take in a day?

A: If you have been told to take a vitamin D supplement by your physician, a dose between 400-800 International Units (IU) per day is safe and potent. Patients on certain medications may need extra vitamin D. Older patients should take the 800 IU per day dose if directed to take over-the-counter Vitamin D by their doctor. For adults, the tolerable upper intake level (UL) of vitamin D is 2,000 IU per day. So, 2700 IUs is higher than the recommended maximum daily dose. Keep in mind that if you are also taking a daily multivitamin, almost all multivitamins already contain 400 IU per day. Also, many calcium supplements also contain vitamin D in the right amount. Consult with your doctor about how much Vitamin D you should specifically be taking.

Q: How much Vitamin D should a person take?

A: The National Institutes of Health suggest an intake of 100 IU to 2,000 IU per day. Most multivitamins have in the neighborhood of 400 IU, which I think is a safe amount, however, it depends on the amount of sunlight that a person gets on a daily basis as well as the consumption of dairy products. In some cases such as asthma or cystic fibrosis, doses higher than normal may be prescribed. You may find the following forum interesting: Matt Curley, PharmD

Q: I'm a 52-year-old, fair-skinned female living in rainy Oregon. I take 50,000 units of vitamin D twice a week and 2,000 units on the other days. I'm taking it for 8 weeks with a prescription, and then will go in to test my vitamin D levels. Is it possible to get too much vitamin D?

A: Vitamin D has many functions in the human body. It helps the body absorb calcium and grow healthy bones, and it reduces inflammation. Current research has shown that vitamin D is also involved in cell growth and differentiation, cell death, and blood vessel generation. The difficulty with vitamin D is that it is naturally present in very few foods. The best sources are fatty fish, including salmon, tuna, and mackerel. Fortified foods, such as milk, provide most of the vitamin D in American diets. Vitamin D is made in our bodies when our skin is exposed to ultraviolet rays from the sun (1).

Q: Since Welchol blocks absorption of vitamin D, what time of day should vitamin D be taken?

A: According to the patient information for Welchol, the recommendation is to take vitamin D at least four hours prior to taking Welchol. It doesn't really matter what time of day you take it, just as long as the spacing between the two medications is adequate. If you have any other questions regarding your medication, feel free to submit another question on our "Ask a Pharmacist" site. Megan Uehara, PharmD

Q: Why am I taking 50,000 units of vitamin D once per week for six weeks?

A: The major function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D helps in the absorption of calcium, helping to form and maintain strong bones. In adults, vitamin D deficiency can lead to osteomalacia, which results in muscular weakness in addition to weak bones. Recent research also suggests vitamin D may provide protection from osteoporosis, hypertension (high blood pressure), cancer, and several autoimmune diseases. Vitamin D can also be given to patients who have limited sun exposure and individuals who are at risk of vitamin D deficiency because they cannot absorb fat (e.g., cystic fibrosis) or inflammatory bowel disease (e.g., Crohn's disease). There are also other conditions that vitamin D is used to treat that may not be listed here. Typically, 50,000 IU of vitamin D is prescribed short term to treat vitamin D deficiency. It is best to speak with your doctor to find out the specific reason why vitamin D was prescribed.

Q: I took a blood test recently and I was very low on Vitamin D, I was told to take 5000 IU by a doctor at Life Extension magazine. It is dangerous to take it long periods of time? How long should I stay on 5,000 IUs? I never take any sun in the summer.

A: The dose of vitamin D depends on which form you take. Cholecalciferol is Vitamin D3. Cholecalciferol is used to treat or prevent many conditions caused by a lack of Vitamin D, especially conditions of the skin or bones. Ergocalciferol is Vitamin D2. All Vitamin D is important for the absorption of calcium from the stomach and for the functioning of calcium in the body. Regardless of the form, too much vitamin D can be dangerous. Your personal health care provider is best able to guide your treatment decisions and should be consulted for recommendations on Vitamin D therapy based on your specific circumstances. Seek emergency medical attention if you think you have used too much of this medicine. An overdose of vitamin D can cause serious or life-threatening side effects. Overdose symptoms may include headache, weakness, drowsiness, dry mouth, nausea, vomiting, constipation, muscle or bone pain, metallic taste in the mouth, weight loss, itchy skin, changes in heart rate, loss of interest in sex, confusion, unusual thoughts or behavior, feeling unusually hot, severe pain in your upper stomach spreading to your back, or fainting. Sarah McKenney Lewis, PharmD

Q: What is the difference between vitamin D and vitamin D3? How much should a 61 year old take?

A: There are two main forms of Vitamin D: cholecalciferol and ergocalciferol. Cholecalciferol is vitamin D3. Vitamin D supplements are made from the ergocalciferol form or vitamin D2. Vitamin D3 is well absorbed in the body but Vitamin D2 is not. Vitamin D2 must be converted into vitamin D3 for the body to absorb it. It takes quite a large amount of vitamin D2 to make a small amount of vitamin D3. Therefore, theoretically, the vitamin D3 supplements should be absorbed more readily in the body. The problem is that most supplements are not regulated so there can be a variable amount between bottles and brands of supplements. It is important to read labels carefully and consult with a physician if there are any concerns. Kimberly Hotz, PharmD

Q: How much vitamin D is safe to take and is it hard on your kidneys or liver?

A: Vitamin D is a fat soluble vitamin that is sold as a dietary supplement. Vitamin D is produced naturally in the body when ultraviolet rays from the sun reach the skin and trigger the production of the vitamin. Vitamin D is involved with many processes in the body including bone health, protection from osteoporosis in older adults, neuromuscular and immune functions, reduction of inflammation, and various other roles in the body. The proper level of Vitamin D is under great debate and discussion currently in the medical field. Talk with your physician to determine what Vitamin D level is ideal for you. Blood work can be done to determine what your current Vitamin D level is at. In patients that are found to be deficient in vitamin D through lab work, physicians may recommend supplementation. The Food and Nutrition Board at the Institute of Medicine for National Academies provides recommendations on the amount of Vitamin D that should be taken by healthy adults. The Adequate Intake (AI) is a reference that is used when there is insufficient evidence to determine a RDA (recommended daily allowance). The AI for Vitamin D is made with the assumption that vitamin D is not being synthesized via exposure by sunlight. For healthy patients 51-70 years of age, the AI for Vitamin D is 400 IU for both men and women. However, an expert committee was established in 2008 and will reexamine the recommendations for vitamin D supplementation. This committee was established after substantial new research supports examining the current recommendations. Vitamin D is classified as a dietary supplement. Because dietary supplements have not been thoroughly studied in the clinical setting, possible side effects and interactions with other drugs are not well known. Also because supplements are not strictly regulated by the U.S. Food and Drug Administration (FDA), these products are not required to be tested for effectiveness, purity or safety. In general, dietary supplements should only be taken under the supervision of your health care provider. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Jen Marsico, RPh

Q: What possible side effects should I look for while taking vitamin D 50000 weekly for 8 weeks?

A: The role of vitamin D in the body includes maintaining normal blood levels of calcium and phosphorus. Vitamin D helps with the absorption of calcium, which creates and maintains strong bones. Some studies indicate that vitamin D may prevent osteoporosis, high blood pressure, cancer, and certain autoimmune conditions. Two forms of vitamin D are important to the body – vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D2 is made by plants whereas vitamin D3 is made in the skin upon exposure to ultraviolet-B (UVB) rays from sunlight. In addition, some foods are fortified with Vitamin D2 or Vitamin D3. In some people, supplemented vitamin D is used to treat certain conditions. Prescription only vitamin D (ergocalciferol) 50,000 units capsules are used to treat hypoparathyroidism (an endocrine disorder, where parathyroid glands in the neck do not provide enough parathyroid hormone); refractory rickets (soft, weak bones from a lack of vitamin D that does not respond to usual doses of vitamin D); and familial hypophosphatemia (low levels of blood phosphate, which is common in certain families). Side effects with vitamin D (ergocalciferol) 50,000 units capsules are related to hypervitaminosis D (excessive vitamin D) and include impaired kidney function with excessive urination (including at night), excessive thirst, elevated calcium in the urine, higher than normal nitrogen containing compounds in the blood, high blood pressure, excessive calcium deposits in the kidney, calcium build up in blood vessels, or insufficient kidney function that may cause death; mental retardation; calcium build up in soft tissues, such as the heart, blood vessels, kidneys, and lungs; loss of bone (osteoporosis) in adults; dwarfism in children; aches, stiffness, and weakness; nausea; decreased appetite; constipation; elevated blood acidity; anemia; and weight loss. This may not be a complete list of the side effects associated with vitamin D. When your doctor prescribes a new medication, be sure to discuss all your prescription and over-the-counter drugs, including dietary supplements, vitamins, botanicals, minerals, and herbals, as well as the foods you eat. Always keep a current list of the drugs and supplements you take and review it with your healthcare providers and your pharmacist. If possible, use one pharmacy for all your prescription medications and over-the-counter products. This allows your pharmacist to keep a complete record of all your prescription drugs and to advise you about drug interactions and side effects. Tell your health-care provider about any negative side effects from prescription drugs. You can also report them to the U.S. Food and Drug Administration by visiting www.fda.gov/medwatch or by calling 1-800-FDA-1088. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Derek Dore, PharmD

Q: Just wandering about vitamin D, and how it can help depression. I have been off Celexa for 9 days now, and I take 800 of vitamin D and 1200 calcium.

A: Vitamin D has many functions in the human body. It helps the body absorb calcium and grow healthy bones, and it reduces inflammation. Current research has shown that vitamin D is also involved in cell growth and differentiation, cell death, and blood vessel generation. According to the National Institute of Health, there is no scientific evidence that vitamin D has an effect on depression. When your doctor prescribes a new medication, be sure to discuss all your prescription and over-the-counter drugs, including dietary supplements, vitamins, botanicals, minerals, and herbals, as well as the foods you eat. Always keep a current list of the drugs and supplements you take and review it with your healthcare providers and your pharmacist. If possible, use one pharmacy for all your prescription medications and over-the-counter products. This allows your pharmacist to keep a complete record of all your prescription drugs and to advise you about drug interactions and side effects. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Michelle McDermott, RPh

Q: I have heard that increasing your vitamin D intake will help you loose weight. If so, how much do you need to increase the dose of vitamin D each day.

A: There are no vitamins or supplements proven to increase metabolism or promote weight loss. In general, vitamins play an important role in the body

Q: I take vitamin D once a week. Since I've been taking it, my knees and legs hurt. Could I be getting too much vitamin D?

A: It is possible to get an overdose of vitamin D, and this can give symptoms of bone and muscle pain. Your doctor can tell if you're getting too much vitamin D through a blood test. Vitamin D2 is a form of vitamin D that's available as a prescription strength tablet or injection. Vitamin D2 is used to treat a vitamin D deficiency, low phosphate levels, rickets, osteoporosis, or hypoparathyroidism. A typical prescription dose of vitamin D2 tablets is 50,000 IU weekly. For some conditions, it's only taken for a short amount of time — a few months, for example. Discuss your symptoms with your doctor and ask if you can have your vitamin D level checked. For more information vitamin D2, go to . Laura Cable, PharmD

Q: If you take an excessive amount of vitamin D, what effect will it have on your body?

A: An excessive intake of Vitamin D can cause serious or even life-threatening side effects. Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include headache, weakness, drowsiness, dry mouth, nausea, vomiting, constipation, muscle or bone pain, metallic taste in the mouth, weight loss, itchy skin, changes in heart rate, loss of interest in sex, confusion, unusual thoughts or behavior, feeling unusually hot, severe pain in your upper stomach spreading to your back, or fainting. In general, dietary supplements should only be taken under the supervision of your health care provider. Gregory Latham, RPh

Q: My doctor has prescribed 50,000 IU of vitamin D once a month. I am paying $10 each month for them. Can I take over-the-counter vitamin D in an amount to equal 50,000 IU's over the whole month?

A: Vitamin D comes in two forms, Vitamin D2 and Vitamin D3. Typically, the prescription form is Vitamin D2, also known as ergocalciferol. The over-the-counter Vitamin D is usually Vitamin D3, also referred to as cholecalciferol. Prescription strength Vitamin D usually comes in 50,000 units. The over-the-counter Vitamin D usually comes in doses of 400 – 1000 units. For patients who have been diagnosed with a vitamin D deficiency, they normally respond better to the higher dosage of Vitamin D2. Thus if your doctor is recommending you take the prescription formulation, you shouldn't take the over-the-counter product without consent from your physician. Often times, after the vitamin D levels return to normal, the doctor will have you take an over-the-counter vitamin D on a daily basis. Megan Uehara, PharmD

Q: I take a multivitamin and calcium + vitamin D. Is it necessary to take extra vitamin D? Is it possible to take too much vitamin D?

A: Vitamin D is found in many dietary sources such as fish, eggs, fortified milk, and cod liver oil. The sun also contributes significantly to the daily production of vitamin D, and as little as 10 minutes of exposure is thought to be enough to prevent deficiencies. The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. Recently, research also suggests vitamin D may provide protection from osteoporosis, hypertension (high blood pressure), cancer, and several autoimmune diseases. The Adequate Intake (AI) levels have been established by the U.S. Institute of Medicine of the National Academy of Sciences. Recommendations are: For all individuals from 50-70 years-old, 10 micrograms daily (400 IU) is recommended. Vitamin D toxicity can result from regular excess intake of this vitamin, and may lead to hypercalcemia (increased levels of calcium in the blood) and excess bone loss. You should not increase the intake of Vitamin D beyond what you are getting through the calcium and vitamin supplements without your physicians approval. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Lori Poulin, PharmD

Q: How can vitamin D help kidney infection?

A: Vitamin D is activated by a first step in the liver and then a second step in the kidneys. If the kidneys are not working properly, they may not be able to do their part in activating vitamin D. Your doctor can check your kidney function with simple lab tests. If your doctor determines that your kidneys are not working properly during an infection, it may be necessary to give vitamin D in the already activated form. Calcitriol is an already activated form of vitamin D that can be used to provide vitamin D to people who are not capable of activating it. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications. Sarah Lewis, RPh, PharmD

Q: Can Vitamin D3 cause constipation? I have been on Caltrate 600+D (1 tablet daily) for quite a few years. Recently, my primary physician had me start taking two of the Caltrate 600+D pills daily and she also added Vitamin D3, 1000 units. I have been on the Vitamin D3 now for about one month and have started having constipation which I did not have before.

A: Vitamin D3 or cholecalciferol is a D vitamin that is important for the absorption of calcium from the stomach and for the functioning of calcium in the body.It is used to treat or prevent many conditions caused by a lack of vitamin D, especially conditions of the skin or bones. Calcium is a mineral that is found naturally in foods that is necessary for many normal functions of your body, especially bone formation and maintenance. Calcium and vitamin D combinations are used to prevent or to treat a calcium deficiency. Constipation can be a common side effect of calcium. Since your dose of Caltrate has been increased, constipation may be due to taking more calcium. However, constipation can also be a sign of early vitamin D overdose. It is possible to get too much vitamin D and an overdose can cause serious, even life-threatening side effects. Other symptoms of early vitamin D overdose include weakness, metallic taste in your mouth, weight loss, nausea, vomiting, and muscle or bone pain. Contact your doctor for proper evaluation of your constipation and to make sure your body does not have too much vitamin D. Seek emergency medical attention if you think you are experiencing symptoms of a vitamin D overdose. Your health care provider is best able to properly evaluate your medical condition and give recommendations based on your specific circumstances. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications. Sarah Lewis, RPh, PharmD

Q: Why do I need vitamin D if I have a liver infection?

A: Vitamin D is important for the absorption of calcium from the stomach and for the functioning of calcium in the body. Vitamin D also plays a role in the function of nerves, muscles, and the immune system. The skin can produce vitamin D with just 5-30 minutes of sun exposure (without sunscreen) a few times a week. Vitamin D is also found in foods such as salmon, tuna, mackerel, and fortified dairy products (milk, yogurt, etc). However, the vitamin D from these sources is inactive until it is changed by the liver and then the kidneys into the active form of the vitamin. Your doctor can tell how well your liver and your kidneys are working by drawing blood and checking certain laboratory tests. Your liver function tests (LFTs) can help your doctor determine if your liver is working properly. If your LFTs show that your liver is not working as it should (for whatever reason), it may not be able to do its job in activating vitamin D so your body can use it. In that case, a vitamin D deficiency could develop and it may be necessary to take a vitamin D supplement that is already in the active form. Calcitriol is the active form of vitamin D. It is used to treat calcium deficiency with hypoparathyroidism (decreased functioning of the parathyroid glands) and metabolic bone disease in people with chronic kidney failure. Calcitriol does not have to undergo activation in the body, so it can be used in people kidney or liver problems. Your doctor or health care provider is best able to properly evaluate your medical condition and give recommendations based on your specific circumstances. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications. Sarah Lewis, RPh

Q: How much vitamin D is too much? I'm currently taking 2,400 IU. I have rheumatoid arthritis.

A: Vitamin D (ergocalciferol) () is a supplement used for hyperparathyroidism. Side effects associated with Vitamin D include nausea, constipation, and weight loss. Take Vitamin D exactly as prescribed. Consult with your doctor about a dose for your current condition. It is important when your doctor prescribes a new medication, be sure to discuss all your prescription medications and over-the-counter drugs, including dietary supplements, vitamins, botanicals, minerals and herbals, as well as foods you eat. Always keep a current list of the drugs and supplements you take and review it with your health care providers and your pharmacist. If possible, use one pharmacy for all your prescriptions and over-the-counter products. This allows your pharmacist to keep a complete record of all your prescription drugs and advise you about drug interactions and side effects. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Kimberly Hotz, PharmD

Q: Can too much vitamin D, 2,000 units per day, cause skin conditions such as itch, hives, pink itchy spots, etc?

A: Vitamin D is used to help with the absorption of calcium, to promote healthy bones and prevent osteoporosis. The upper end dose should not exceed 2,000 units per day, as it is not water-soluble and can build up toxic levels in the fat. An allergic reaction from Vitamin D may include itch, hives, and pink itchy spots, but the symptoms of itchy skin can also come from a high dose. You should contact your doctor for a proper diagnosis, and the doctor may have you reduce your dose. Other side effects may include excessive thirst, metallic taste, poor appetite, weight loss, bone pain, tiredness, sore eyes, vomiting, diarrhea, constipation, frequent need to urinate, and muscle problems. This is not a complete list of the side effects associated with Vitamin D. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. When your doctor prescribes a new medication, be sure to discuss all your prescription and over-the-counter drugs, including dietary supplements, vitamins, botanicals, minerals, and herbals, as well as the foods you eat. Always keep a current list of the drugs and supplements you take and review it with your health care providers and your pharmacist. If possible, use one pharmacy for all your prescription medications and over-the-counter products. This allows your pharmacist to keep a complete record of all your prescription drugs and to advise you about drug interactions and side effects. Tell your health care provider about any negative side effects from prescription drugs. You can also report them to the U.S. Food and Drug Administration by visiting www.fda.gov/medwatch or by calling 1-800-FDA-1088. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Patti Brown, PharmD

Q: Can vitamin D be absorbed from the sun through glass such as a car window?

A: Ultraviolet light (UV rays) from the sun initiates the conversion of substances in the skin to cholecalciferol. Cholecalciferol is changed in the liver to another substance called calcidiol which moves on to the kidney where it is converted into calcitriol. Calcitriol is the active form of Vitamin D that contributes to healthy bones, heart, and protects against health conditions. Attempts to acquire sunlight through glass windows fail to help the body make vitamin D. This is because UV light does not pass through window glass effectively. It is said that we only need between 5 and 15 minutes of sunlight to the skin of either the face, arms, legs or back, twice a week to get the needed amount of vitamin D. For more information on vitamin D, visit . For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Lori Poulin, PharmD

Q: What are the benefits of vitamin D, and what are the sources?

A: Vitamin D has many functions in the human body. It helps the body absorb calcium and grow healthy bones, and it reduces inflammation. Current research has shown that vitamin D is also involved in cell growth and differentiation, cell death, and blood vessel generation. The difficulty with vitamin D is that it is naturally present in very few foods. The best sources are fatty fish, including salmon, tuna, and mackerel. Fortified foods, such as milk, provide most of the vitamin D in American diets. Vitamin D is made in our bodies when our skin is exposed to ultraviolet rays from the sun.

Q: Will my low count of vitamin D cause high blood pressure?

A: Vitamin D is important to many functions of the body, according to the National Institutes of Health Office of Dietary Supplements (NIHODS). Vitamin D assists the body in absorbing calcium, which maintains strong bones. Vitamin D is also needed by muscles — to allow them to move. Nerves need vitamin D to communicate between the brain and areas of the body. The immune system needs vitamin D to battle bacteria and viruses. Vitamin D is found in cells in many areas of the body. According to the NIHODS, vitamin D is obtained in three ways — through the skin, dietary intake, and through supplements. The body makes vitamin D following exposure to sunlight. Foods rich in vitamin D include: egg yolks, fish from saltwater, liver, and milk and cereals fortified with vitamin D. There is a wide array of vitamin D supplements. Vitamin D deficiency can lead to soft, thin and brittle bones. Thus, vitamin D deficiency can cause bone diseases; specifically rickets in children and osteoporosis in adults. According to NIHODS, vitamin D is being studied to determine its connection to certain medical conditions, such as diabetes, autoimmune conditions (e.g., multiple sclerosis), certain types of cancer, bone disorders, and high blood pressure. A recent National Institute of Arthritis and Musculoskeletal and Skin Diseases-funded study found that vitamin D deficiency in younger women was associated with increased risk of high blood pressure in mid-life. High blood pressure increased from 6% to 25% over a 15 year period in a group of women with an average age of 38 years. The study found that women who had vitamin D deficiency in the years before menopause were at 3 times increased risk of developing high blood pressure in mid-life. According to NIHODS, people who may need extra vitamin D include: older adults; breastfed infants; darker skin individuals; people with certain medical conditions, like liver diseases, cystic fibrosis, and Crohn's disease; obese people; and people who have had gastric bypass surgery. There are risks associated with getting too much vitamin D. The appropriate levels of vitamin D in the body and the recommended intake of vitamin D are best determined by a person's doctor or health care provider. Derek Dore, PharmD

Q: Will vitamin D cause blood in the stool?

A: Vitamin D is important to many functions of the body, according to the National Institutes of Health Office of Dietary Supplements (NIHODS). Vitamin D assists the body in absorbing calcium, which maintains strong bones. Vitamin D is also needed by muscles — to allow them to move. Nerves need vitamin D to communicate between the brain and areas of the body. The immune system needs vitamin D to battle bacteria and viruses. Vitamin D is found in cells in many areas of the body. According to the NIHODS, vitamin D is obtained in three ways — through the skin, dietary intake, and through supplements. The body makes vitamin D following exposure to sunlight. Foods rich in vitamin D include: egg yolks, fish from saltwater, liver, and milk and cereals fortified with vitamin D. There is a wide array of vitamin D supplements. Vitamin D deficiency can lead to soft, thin and brittle bones. Thus, vitamin D deficiency can cause bone diseases; specifically rickets in children and osteoporosis in adults. According to NIHODS, vitamin D is being studied to determine its connection to certain medical conditions, such as diabetes, autoimmune conditions (e.g., multiple sclerosis), certain types of cancer, bone disorders, and high blood pressure. According to NIHODS, people who may need extra vitamin D include: older adults; breastfed infants; darker skin individuals; people with certain medical conditions, like liver diseases, cystic fibrosis, and Crohn's disease; obese people; and people who have had gastric bypass surgery. There are health risks associated with getting too much vitamin D. Vitamin D toxicity can cause symptoms like nausea, vomiting, poor appetite, constipation, weakness, and weight loss, according to NIHODS. Excessive vitamin D can also cause mental status changes; abnormalities in heart rhythm; kidney stones; and accumulation of calcium and phosphate in the kidneys and other tissues. Vitamin D was not identified as a cause of blood in stools; however, this does not necessarily mean that vitamin D does not cause blood in the stools. The appropriate levels of vitamin D in the body and the recommended intake of vitamin D are best determined by a person's doctor or health care provider. Derek Dore, PharmD

Q: What is the recommended dose of vitamin D for a person with low vitamin D levels as noted on a blood test?

A: Currently, there is no Recommended Daily Allowance (RDA) that has been established for vitamin D. This is due to insufficient clinical evidence to determine how much vitamin D should be taken. There is an Adequate Intake (AI) level that has been determined for Vitamin D. Adequate Intake levels are the level of intake that is needed to maintain healthy blood levels of a vitamin. Vitamin D and calcium work together, and thus it is important to get enough calcium as well. Calcium can be obtained through foods that we eat or through supplements that we take. If the levels of Vitamin D are low, the doctor who ordered the blood test should determine if treatment is necessary and how much vitamin D is needed. There are two different types of Vitamin D and your doctor should tell you which one to take and in what amount. Megan Uehara, PharmD

Q: Which foods are high in vitamin D and why do I need it?

A: Vitamin D (ergocalciferol) is a fat soluble nutrient used to help calcium be absorbed into the body to prevent osteoporosis. It is also used to treat hypoparathyroidism (decreased function of the parathroid glands), and for rickets (softening of the bones in vitamin D deficiency) or low levels of phosphate in the blood. According to the National Institutes of Health, the best way to get enough vitamins is to eat a balanced diet with a variety of foods. Fatty fish, such as salmon, mackerel, tuna, eel, catfish, and sardines, eggs, meat, and mushrooms have a large amount of vitamin D, and many foods, such as milk, and cereal are fortified with vitamin D. The sun is also an excellent source of vitamin D. In some cases, a daily multivitamin may be needed for optimal health. The Food and Nutrition Board at the Institute of Medicine of the National Academies recommends a daily intake of 600 IU for the age of 71 years and up. There are numerous formulations and different combinations of vitamins and minerals. The need for vitamin supplementation and the choice of the most appropriate vitamin preparation may depend on many patient-specific characteristics. Thus, it is important to consult with your physician or health care provider regarding the intake of vitamins. Because herbs and supplements are not strictly regulated by the U.S. Food and Drug Administration, these products are not required to be tested for effectiveness, purity, or safety. In general, dietary supplements should only be taken under the supervision of your health care provider. Patti Brown, PharmD

Q: My wife takes Vitamin D and is having various side effects. What should she expect?

A: Vitamin D (ergocalciferol) is a vitamin available over-the-counter and as a prescription for the treatment of hypoparathyroidsim, rickets, and to help with the absorption of calcium. Take Vitamin D (ergocalciferol) exactly as prescribed by your physician or as instructed on the over-the-counter medication bottle. Taking too much vitamin D (ergocalciferol) can cause problems including headache, weakness, drowsiness, dry mouth, nausea, vomiting, constipation, muscle or bone pain, metallic taste in the mouth, weight loss, itchy skin, changes in heart rate, loss of interest in sex, confusion, unusual thoughts or behavior, feeling unusually hot, severe pain in your upper stomach spreading to your back, or fainting. Stop taking Vitamin D and call your doctor immediately if you have any of the following serious side effects including: thinking problems, changes in behavior, feeling irritable, urinating more than usual, chest pain, feeling short of breath; or early signs of vitamin D overdose (weakness, metallic taste in your mouth, weight loss, muscle or bone pain, constipation, nausea, and vomiting. For more information on Vitamin D (ergocalciferol), visit our Web site . When your doctor prescribes a new medication, be sure to discuss all your prescription and over-the-counter drugs, including dietary supplements, vitamins, botanicals, minerals, and herbals, as well as the foods you eat. Always keep a current list of the drugs and supplements you take and review it with your health care providers and your pharmacist. If possible, use one pharmacy for all your prescription medications and over-the-counter products. This allows your pharmacist to keep a complete record of all your prescription drugs and to advise you about drug interactions and side effects. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Jennifer Carey, PharmD

Q: I took a blood test recently and I was very low on vitamin D. I was told to take 5000 IU by a doctor at a magazine. Is it dangerous to take it for long periods of time? How long should I stay on 5000 IU? I never go in the sun in the summer.

A: The dose of vitamin D depends on which form you take. Cholecalciferol is vitamin D3. Cholecalciferol is used to treat or prevent many conditions caused by a lack of vitamin D, especially conditions of the skin or bones. Ergocalciferol is vitamin D2. All vitamin D is important for the absorption of calcium from the stomach and for the functioning of calcium in the body. Regardless of the form, too much vitamin D can be dangerous. Your personal health care provider is best able to guide your treatment decisions and should be consulted for recommendations on vitamin D therapy based on your specific circumstances. Seek emergency medical attention if you think you have used too much of this medicine. An overdose of vitamin D can cause serious or life-threatening side effects. Overdose symptoms may include headache, weakness, drowsiness, dry mouth, nausea, vomiting, constipation, muscle or bone pain, metallic taste in the mouth, weight loss, itchy skin, changes in heart rate, loss of interest in sex, confusion, unusual thoughts or behavior, feeling unusually hot, severe pain in your upper stomach spreading to your back, or fainting. Sarah Lewis, PharmD

Q: My doctor has me taking what seems like a high dose of vitamin D every week. How do I know if it's too much?

A: Vitamin D is essential to maintain adequate levels of calcium and phosphorous. Vitamin D aids in the absorption of calcium into the bones and may provide protection from osteoporosis, high blood pressure, cancer, and autoimmune diseases. Since most of us avoid sunlight exposure, research indicates that we should supplement our diet with at least 5,000 units of vitamin D daily. It's not uncommon to see patients taking 50,000 units of vitamin D daily for a month, or 50,000 units per week for several months. As long as you're under the supervision of a physician, you shouldn't have any concern with taking high amounts of vitamin D for a short period of time. However, if you do have concerns, discuss them with your physician so that he or she can explain the reasoning behind prescribing this supplement for you. Regards, Lori Poulin, PharmD

Q: My doctor has me on 50,000 units a week of vitamin D. Is that normal?

A: Vitamin D (ergocalciferol) is important for the absorption of calcium from the stomach and for the functioning of calcium in the body. It can be used for many purposes and the dose is related to what it is being used for. Your dosage, 50,000 units per week, is not uncommon. Further information on vitamin D can be found at .

Q: I recently overextended my foot and had radiating pain from the instep up the leg. I took a few vitamin D3 tablets a few times for one day along with vitamin C and hyaluoric acid. Amazingly, along with keeping the foot elevated, the pain receeded, and I only maintain the ache in the instep, which I know is a weak spot on my body. (I did some in-depth cleaning of my mother's house and bent and kneeled too much for one day.) I'm 60 years old. Can I take the regular vitamin D along with the vitamin D3?

A: Vitamin D is a supplement that aids in the absorption of calcium, treatment of hypoparathyroidism, treatment of rickets, and a new indications show cancer prevention benefits. Recommended dosage for preventing osteoporosis and fractures is 800 to 1,000 IU per day for older adults. Recommended daily dose of vitamin D3 (cholecalciferol) for preventing all types of cancer is 1,100 IU/day in postmenopausal women. Long-term treatment should not exceed 2,000 IU per day. High doses over a long period of time can cause hypercalcemia and other complications. Talk to your doctor about an appropriate dose of vitamin D for you. Do not start or stop any medications or treatments without first talking to the doctor. You can also find helpful information on vitamin D at . Jennifer Carey, PharmD

Q: I am using glucophage (500 ml), Lipitor, and lisinopril, all once a day. I am also taking 2 fish oil tablets a day. My doctor said to start taking vitamin D also. When I went to purchase the vitamin D, there was only D3. Is there a plain vitamin D, or is it okay for me to take the vitamin D3?

A: Vitamin D is available in two forms, cholecalciferol (D3) and ergocalciferol (D2). Our bodies make Vitamin D3 when exposed to sunlight. Vitamin D3 has a longer shelf life than vitamin D2 and vitamin D3 breaks down into calcitrol which has cancer fighting properties. I am not certain why your doctor recommended vitamin D but the following are recommended dosages published by Pharmacist Letter. For preventing osteoporosis and fractures: some experts recommend 800 to 1,000 IU per day for older adults. For preventing falls: 800 to 1,000 IU/day has been used in combination with calcium 1,000 to 1,200 mg/day. For preventing multiple sclerosis (MS): long-term consumption of at least 400 IU per day, mainly in the form of a multivitamin supplement, has been used. For preventing all cancer types: calcium 1,400 to 1,500 mg/day plus vitamin D3 (cholecalciferol) 1,100 IU/day in postmenopausal women has been used. For muscle pain caused by medications called "statins": vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol) 50,000 units once a week or 400 IU daily. Do not stop or start any medications or treatments without first talking to the doctor. You can also find helpful information on vitamin D at . Jennifer Carey, PharmD

Q: Why are so many doctors giving vitamin D in such massive amounts when they have such bad side effects?

A: Patients often inquire about appropriate vitamin supplementation. Vitamin D is important for the absorption of calcium from the stomach and for proper functioning of calcium in the body. Vitamin D is a fat soluble vitamin and an excessive intake can cause unwanted side effects. The Recommended Dietary Allowance (RDA) for vitamin D is currently 400 IU for patients between 50 and 70 years of age. 50,000 IU is the prescription dose of vitamin D. According to the U.S. Food and Drug Administration (FDA), this is an approved dose for treatment of certain conditions. An excessive intake of Vitamin D can cause side effects including nausea, vomiting , constipation, and weakness and can affect calcium levels causing other dangerous side effects. Supplementation with vitamin D is extremely patient specific and depends on various factors including diet, lifestyle, medical and prescription history and individual risk factors. It is important for your doctor to do routine monitoring while being treated with vitamin D. You may want to contact your health care provider to determine the appropriate intake of titamin D recommended based on your specific needs. It is always important to check with your doctor before taking any vitamins, supplements or over the counter products. Beth Isaac, PharmD

Q: What are the newest findings on taking vitamin D on a regular basis? I read an article in Readers Digest that suggested 1,000 IU per day for everyone.

A: The primary function of vitamin D is to maintain normal levels of calcium and phosphorus within the body. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. Current research also suggests vitamin D may provide protection from osteoporosis, hypertension (high blood pressure), cancer, and several autoimmune diseases. We have an excellent blog article, The Skinny of Vitamin D, on our Web site. The recommendation for adequate vitamin D intake remains unchanged since Adequate Intake (AI) levels were established by the U.S. Institute of Medicine of the National Academy of Sciences. For males and females over age 50 and up to 70 years old, 10 micrograms daily (400 IU) is recommended. Over 70 years old, 15 micrograms daily (600 IU) is suggested. It should be noted that some providers, like those mentioned in the Reader's Digest article, have questioned whether the currently recommended adequate levels are sufficient to meet the body's needs This may especially be the case for those without adequate sunlight exposure. The upper limit (UL) for vitamin D remains unchanged as well at 2,000 IU daily. This is due to potential toxicities that can occur when taken in higher doses. The suggested 1,000 IU daily would therefore fall under the limit and be considered safe and effective. Jeff O'Connell, PharmD

Q: Can it be harmful to take too much vitamin D?

A: Your question concerns the effects of too much vitamin D. You have asked a very good question. Many people think of vitamin supplements as harmless, no matter how much are taken. The truth is that there are two kinds of vitamins, those that are water-soluble and those that are fat-soluble. The water-soluble vitamins include the B vitamins and vitamin C. Any amount of these vitamins taken in excess of the body's needs are simply "washed out" of the body through the kidneys and into the urine. The fat-soluble vitamins are A, D, E, and K. Any excess amounts of these vitamins are saved in the body's fat until such time as they are needed. If large amounts of any of these fat-soluble vitamins are consumed over a period of time, overdosage effects (called toxicities) may result. It is always a good idea to check with one's health care provider in matters like this. Please consult your health care provider for guidance in your specific case. Gregory Latham, MS, RPh

Q: My doctor put me on vitamin D3 2,000 mg daily when I stopped taking Fosamax. Everything I read about it says 1,000 mg is enough. I also take Centrum Silver which has 400 mg vitamin D. Am I overdosing on vitamin D3?

A: Your question regards dosing of vitamin D3. Vitamin D has been in the media quite a bit recently. There has been new information discovered about vitamin D and most remarkably is that many patients are low in this vitamin. Dosing is usually based upon lab results of your current vitamin D level. Labs should be drawn after you are taking vitamin D to determine if the dosing is effective for you. In practice, I have seen 2,000 IU of vitamin D3 once daily prescribed quite frequently and have seen dosages double that and even higher. The dosage should be specific to your levels. As always, please talk with your health care provider regarding questions about your vitamin supplementation. The following link from Everyday Health provides valuable information regarding vitamin D. . Jen Marsico, RPh

Q: Can I take vitamin D and DHEA together on an empty stomach without causing an interaction or a decrease/increase in the effectiveness of these vitamins/hormones?

A: Both Vitamin D and DHEA would better be absorbed and utilized if taken with food. Both substances go through first pass metabolism by the liver, in some cases, the DHEA as with many hormones can be tough on the liver. For that reason, I recommend taking them apart, but with food. Although that is only my professional suggestion. I have had patients who have taken DHEA for years and then one day find that their liver no longer tolerates it. For that reason, I typically recommend that it be taken with food, but with no other forms of medication. Matt Curley, PharmD

Q: How much vitamin D is too much?

A: There are two different forms of vitamin D, D2 or ergocalciferol and D3 or cholecalciferol. The prescription strength vitamin D is ergocalciferol (D2, Drisdol) and comes in a dose of 50,000 international units (IU), which is usually taken once a week. Most of what can be found over the counter is vitamin D3 or cholecalciferol, which comes in lower doses 400 IU or 1000 IU and which should be taken once a day. The maximum recommended dose of vitamin D3 or cholecalciferol is 2,000 IU daily. Patients with a vitamin D deficiency usually will do best on the 50,000 IU vitamin D2 dose for several months until levels return to normal, then it may be possible to be placed on a lower OTC dose daily to maintain levels. Your doctor will be able to tell you what vitamin D dose is best for you based on your blood levels if you are deficient in vitamin D. Please see the following Everyday Health links for more information on the two vitamin D formulations. and Laura Cable, PharmD

Q: What are the benefits of taking vitamin D and how much vitamin D should a 68-year-old woman take on a daily basis? I also take B-12 daily. I have severe scoliosis, anemia, and pain much of the time from degenerative arthritis. I also have a fracture at the L 5 level. I need more energy and relief from the pain.

A: Vitamin D is necessary in order for our bodies to absorb calcium. The calcium will help strengthen our bones and is very important. Thus, the vitamin D is important as well. The normal dose of vitamin D is 400 units/day taken as a supplement. Vitamin D is also found in many foods that we eat and is also made naturally in our bodies when we are exposed to sunlight. All sources of vitamin D should not exceed 2000 units/day. Be sure to take a calcium supplement as well if you are not already doing so. This will help to keep your bones strong and will hopefully be able to relieve some of your pain. Megan Uehara, PharmD

Q: I'm on vitamin D, and I only have to take it once a week. How strong is this? What are the pros and cons of one per day versus one per week?

A: The dose and frequency would depend upon a number of factors. One is whether this is vitamin D2 or vitamin D3. Next is what the clinical condition is that is being treated. It could be just for vitamin D2 or D3 deficiency or it could be necessary to treat a specific condition. The third aspect is age, which you state is 55. It is necessary to know all of these factors in order to determine whether daily, weekly, or monthly is better and in what particular dose. The absorption by your body may be more even if given more frequently, but again, it depends on your underlying health status.

Q: I've been told I was vitamin D deficient. I was given 50,000 units vitamin D for 12 weeks once a week. Is this normal, and will I have to take vitamin D after I'm finished with it and thereafter?

A: Vitamin D is needed for strong bones and teeth. Lack of vitmain D may lead to a condition called rickets, especially in children, where bones and teeth are weak. Adults can experience osteomalacia or the loss of calcium from bones causing the bones to become weak. Vitamin D is in a long-acting prescription form that the doctor might prescribe. It is also available over the counter as a supplement. Vitamin D is also found in food sources such as fish, fish liver oils, and vitamin D fortified milk. Vitamin D is also made in the skin when an individual is exposed to sunlight. An individual would need at least 1.5 to 2 hours a week in the sunlight to get the vitamin D needed. Vitamin D is stored in the body; therefore, when you take more than the body needs, it will build up in the body. This may lead to poisoning. Problems are more likely to occur in adults taking 20,000 to 80,000 units a day and more for several weeks or months and children taking 2,000 to 4,000 units a day for several months. A dose of 50,000 units once a week is common to take for vitamin D deficiency. The physician will determine if vitamin D will be continued after the initial treatment. Consult with a physician for any concerns. Kimberly Hotz, PharmD

Q: I have MS and heard that I should be taking 4,000 IU of vitamin D a day. Is there any risk in taking such high doses of vitamin D?

A: Vitamin D is needed for strong bones and teeth. Lack of vitmain D may lead to a condition called rickets, especially in children, where bones and teeth are weak. Adults can experience osteomalacia or the loss of calcium from bones causing the bones to become weak. Vitamin D is in a long-acting prescription form that the doctor might prescribe. It is also available over the counter as a supplement. Vitamin D is also found in food sources such as fish, fish liver oils, and vitamin D fortified milk. Vitamin D is also made in the skin when an individual is exposed to sunlight. An individual would need at least 1.5 to 2 hours a week in the sunlight to get the vitamin D needed. Vitamin D is stored in the body; therefore, when you take more than the body needs, it will build up in the body. This may lead to poisoning. Problems are more likely to occur in adults taking 20,000 to 80,000 units a day and more for several weeks or months and children taking 2,000 to 4,000 Units a day for several months. Consult with a physician for any concerns. Kimberly Hotz, PharmD

Q: What is the vitamin D recommendation for 50+ women?

A: The current daily recommended dose of vitamin D for adults 50 and older is 400 to 600 international units (IU). Many researchers believe that a higher amount is warranted because of the many health benefits. The National Osteoporosis Foundation recommends a daily intake of 800 to 1,000 IU per day for adults over age 50. The upper daily limit considered safe for use is 2,000 IU per day, but there's debate about this level. Very large doses of vitamin D taken over time can cause ill effects, including nausea, vomiting, poor appetite, constipation, weakness, and weight loss.

Q: What is vitamin D good for?

A: In a normal health adult with regular diet, vitamin D supplement is not necessary. With the help of sunlight, the body produces enough vitamin D for normal body function. Vitamin D plays many functions in the body, but it is mainly responsible for bone formation. In some people, such as the elderly, vitamin D supplement is necessary to prevent bone degeneration. People may also use vitamin D if they have hypoparathyroidism, cancer, multiple sclerosis, rheumatoid arthritis, weight loss, and psoriasis. There are other uses for vitamin D, but there exists limited data to support their effectiveness. Lori Mendoza, PharmD

Q: I'm on prescription strength vitamin D 50,000 IU every other week. I was taking it weekly, but my doc cut me back when my vitamin D level improved. Can I take an OTC vitamin D (say 2,000 IU) on a daily basis rather than the mega dose every other week? It would seem to me that it is better to have a constant level in the system rather than highs and lows depending on which day of the week it is. Also, I think it would be cheaper. The prescription vitamin D is expensive and not covered by Medicare Part D. But which is most beneficial to me?

A: The vitamin D that is prescription and is 50,000 IU is vitamin D2 (ergocalciferol). The over-the-counter vitamin D is vitamin D3 (cholecalciferol). Each is absorbed differently by the body and therefore they have different bioequivalence. If you were to change from one to the other, you would need to work with your doctor to determine the dose of the over-the-counter vitamin D3 that would come closest to the absorption that you are getting now with the vitamin D2. Since the absorption by the body is different, your physician may have some other reason why he or she is maintaining you on the prescription vitamin D2 rather than the vitamin D3.

Q: What is ergocalciferol used for?

A: Vitamin D (ergocalciferol) is a supplement used for treating low parathyroid hormone levels, rickets and low phosphate levels in the body. Vitamin D works by promoting absorption and use of calcium and phosphate in the body and also regulating the parathyroid hormone levels. Vitamin D can be taken with or without food but the capsules should be swallowed whole. Do not take Vitamin D 1 hour before or 2 hours after mineral oil. Common side effects of Vitamin D include constipation, loss of appetite, weight loss and nausea. Vitamin D is available as a prescription in 50,000 USP unit capsules. Vitamin D supplements are also available over-the-counter by many different manufacturers. However, supplements and vitamins sold over-the-counter are not monitored by the Food and Drug Administration (FDA). Since the supplements have not been strictly regulated by the Food and Drug Administration, the products are not required to be tested for effectiveness, purity and safety. Because dietary supplements have not been thoroughly studied in the clinical setting, possible side effects and interactions with other drugs are not well known. In general, dietary supplements should only be taken under the supervision of your health care provider. For more specific information, consult with your pharmacist about the potential for drug interactions based on your specific condition and current medications, particularly before taking any action. Vitamin D is a fat-soluble vitamin so overuse could possible cause toxic levels. Dosage levels of Vitamin D should be individualized and closely monitored by the healthcare provider. Consult with the healthcare provider about the intake of Vitamin D fortified foods, dietary supplements and prescription medications. Consult with your healthcare provider regarding any additional concerns. Kimberly Hotz, PharmD

Q: My psychiatrist put me on 1000 units of vitamin D3 a day. I went out and bought two bottles of it. When I went back to see her again, she prescribed 50,000 units once a week and wrote me a prescription. I was wondering can I take 7 of the vitamin d3 a day until I use up all the bottles I have? Would that be the same as taking the 50,000 units once a week?

A: Vitamin D (ergocalciferol) is a supplement used for treating low parathyroid hormone levels, rickets and low phosphate levels in the body. Vitamin D works by promoting absorption and use of calcium and phosphate in the body and also regulating the parathyroid hormone levels. Vitamin D can be taken with or without food but the capsules should be swallowed whole. Do not take Vitamin D 1 hour before or 2 hours after mineral oil. Common side effects of Vitamin D include constipation, loss of appetite, weight loss and nausea. Vitamin D is available as a prescription in 50,000 USP unit capsules. Vitamin D supplements are also available over-the-counter by many different manufacturers. However, supplements and vitamins sold over-the-counter are not monitored by the U.S. Food and Drug Administration (FDA). Since the supplements have not been strictly regulated by the FDA, the products are not required to be tested for effectiveness, purity and safety. In addition, because dietary supplements have not been thoroughly studied in the clinical setting, possible side effects and interactions with other drugs are not well known. In general, dietary supplements should only be taken under the supervision of your health care provider. Consult with your doctor regarding the appropriate way to take the vitamin D you have been prescribed. Kimberly Hotz, PharmD

Q: I was instructed to take 4000 IU of vitamin D3 by my primary physician. After several months, I have lost 9 pounds and also have developed urgent and loose bowel movements? Are these symptoms related to the vitamin D3?

A: Vitamin D can become harmful when amounts in the blood become too high, according to the Office of Dietary Supplements. Signs of vitamin D toxicity include nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Vitamin D toxicity can damage the kidneys. And if too much vitamin D causes high levels of calcium, this can lead to cause confusion, disorientation, and problems with heart rhythm. Urgent and loose bowel movements were not identified as a side effect with vitamin D; however, this does not necessarily mean that these side effects may not happen with the use of vitamin D supplements. Vitamin D is important to the body. Vitamin D helps maintain normal blood levels of calcium and phosphorus. Vitamin D helps with the absorption of calcium, which creates and maintains strong bones. Vitamin D is important to muscles, nerves and the immune system as well. Some studies indicate that vitamin D may prevent osteoporosis, high blood pressure, cancer, and certain autoimmune conditions. Two forms of vitamin D are important to the body — vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D2 is made by plants whereas vitamin D3 is made in the skin upon exposure to ultraviolet-B (UVB) rays from sunlight. In addition, some foods are fortified with Vitamin D. People can get vitamin D through the skin, the diet, and supplements. People who made need extra vitamin D include: older adults; breastfed infants; dark skin people; obese individuals; people who have had gastric bypass surgery; and people with Crohn's disease; cystic fibrosis; or liver diseases. There are many vitamin D supplements available. Both vitamin D2 and vitamin D3 may be found in supplements; however, many supplements now provide only vitamin D3 instead of D2 because D3 may increase vitamin D levels better than D2 and keep the levels raised a longer time, according to the National Institutes of Health Office of Dietary Supplements. There are many causes of weight loss and bowel problems. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Derek Dore, PharmD

Q: How much vitamin D should a very active, 82 year old male take?

A: According to the Food and Nutrition Board (FNB), the Adequate Intake (AI) for vitamin D for a male greater than 71 years old is 15 mcg or 600 IU daily. The AI is determined to be the amount of vitamin D needed by the body to maintain bone health and assist in calcium metabolism. The dosing of vitamins depends on many patient specific factors, please consult your health care provider in regards to the appropriate vitamin D dose for you. Vitamin D is important to the body. Vitamin D helps maintain normal blood levels of calcium and phosphorus. Vitamin D helps with the absorption of calcium, which creates and maintains strong bones. Vitamin D is important to muscles, nerves and the immune system as well. Some studies indicate that vitamin D may prevent osteoporosis, high blood pressure, cancer, and certain autoimmune conditions. Two forms of vitamin D are important to the body — vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Check with your health care provider regarding which formulation of vitamin D is best for you. Vitamin D2 is made by plants whereas vitamin D3 is made in the skin upon exposure to ultraviolet-B (UVB) rays from sunlight. In addition, some foods are fortified with Vitamin D. People can get vitamin D through the skin, the diet, and supplements. People who made need extra vitamin D include: older adults; breastfed infants; dark skin people; obese individuals; people who have had gastric bypass surgery; and people with Crohn's disease; cystic fibrosis; or liver diseases. There are many vitamin D supplements available. Both vitamin D2 and vitamin D3 may be found in supplements; however, many supplements now provide only vitamin D3 instead of D2 because D3 may increase vitamin D levels better than D2 and keep the levels raised a longer time, according to the National Institutes of Health Office of Dietary Supplements. Vitamin D can become harmful when amounts in the blood become too high, according to the Office of Dietary Supplements. Signs of vitamin D toxicity include nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Vitamin D toxicity can damage the kidneys. And if too much vitamin D causes high levels of calcium, this can lead to cause confusion, disorientation, and problems with heart rhythm. In general, dietary supplements should only be taken under the supervision of your health care provider. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD

Q: I am vitamin D deficient. What dosage of vitamin D should I take on a daily basis?

A: According to the National Institutes of Health, the best way to get enough vitamins is to eat a balanced diet with multiple foods. The United States Recommended Daily Allowance (U.S. RDA) for Vitamin D, used to prevent osteoporosis by helping calcium to be utilized by the bones, is 400 IU per day. If a balanced diet fails to supply the proper amount of vitamin D, a supplement may be required. Some of the vitamins, including vitamin D are fat soluble and toxicity can occur. Other vitamins are water soluble and are just emptied out of the body through the kidneys pumping them into the urine. However, in the case of a vitamin D deficiency, large doses of vitamin D are given for a certain period of time, and then the doctor will access the situation. Diseases that may reportedly result from a vitamin D deficiency may include autism, autoimmune illness, cancer, chronic pain, depression, diabetes, heart disease, hyperparathroidism, hypertension, influenza, myopathy and osteoporosis. Osteoporosis is a concern, as vitamin D is required for the body to absorb calcium, and without calcium, the bones break down. In nursing homes, or where the elderly are unable to get out into the sun, which provides vitamin D, or where they do not take a supplement, they can be harmed more than they would ordinarily be if they fall. A hip or bone could be broken. Doses for deficiency often reach 50,000 IU per week, but under the close monitoring by a doctor for certain periods of time. Some foods can also provide vitamin D, such as oily fish (salmon, mackerel, and blue fish). Milk that is fortified and other dairy products are a good source of vitamin D. Vegetables do not have significant amounts of vitamin D in them. More and more people are not getting enough of the vitamin naturally, and studies are showing that the RDA (recommended daily allowance) may be too low. The future may bring a higher requirement for people on taking vitamin D, but remember it is fat soluble, so it is possible to take too much. Talk to your doctor to determine what dose you need to take. Patti Brown, PharmD

Q: My physican prescribed vitamin D 5000 for 8 weeks and then to continue with 1000 a day after that. I am also hydrochlorothiazide for high blood pressure. Since starting the vitamin D3, I'm having trouble with my muscles and bones hurting on my right arm and shoulder. Could that be from too much vitamin D?

A: Vitamin D3, or cholecalciferol, is a fat-soluble vitamin that is not found in very many foods. It is important for the absorption of calcium from the stomach and functioning in the body. The primary sources of vitamin D are fortified foods, such as dairy products, and the ability of the skin to make vitamin D when it is exposed to sunlight. As we age, the skin becomes less efficient at making vitamin D. Because of this, vitamin D deficiencies can occur in older adults, as well as people who do not eat enough fortified foods or who do not get enough sun exposure. If a deficiency develops, cholecalciferol can be used to treat vitamin D deficiency. It is possible to get too much vitamin D, which can be dangerous. Symptoms of too much vitamin D include headache, weakness, drowsiness, dry mouth, nausea, vomiting, constipation, muscle or bone pain, metallic taste in the mouth, weight loss, itchy skin, changes in heart rate, confusion, severe stomach pain, and fainting. Seek emergency medical attention if you think you have taken too much vitamin D or you are experiencing symptoms of an overdose. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications, particularly before taking any action. Sarah Lewis, PharmD

Q: How does the sun affect vitamin D in our bodies?

A: Vitamin D is a group of fat-soluble secosteroids, the two major physiologically relevant forms of which are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D without a subscript refers to either D2 or D3 or both. Vitamin D is produced in the skin of vertebrates after exposure to ultraviolet B light, and occurs naturally in a small range of foods. In some countries staples such as milk, flour and margarine are artificially fortified with vitamin D, and it is also available as a supplement in pill form. There are two different forms of vitamin D, D2 or ergocalciferol and D3 or cholecalciferol. The prescription strength vitamin D is ergocalciferol (D2, Drisdol) and comes in a dose of 50,000 international units (IU) which is usually taken once a week. Most of the over the counter is vitamin D3 or ergocalciferol comes in lower doses 400 IU or 1000 IU which are to be taken once a day. Patients with a vitamin D deficiency usually will do best on the 50,000 IU dose for several months until levels return to normal, then it may be possible to be placed on a lower OTC dose daily to maintain levels. Most people meet their vitamin D needs through exposure to sunlight. Ultraviolet (UV) B radiation penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3. Season, geographic latitude, time of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis. It has been suggested that approximately 5-30 minutes of sun exposure between 10 AM and 3 PM at least twice a week to the face, arms, legs, or back without sunscreen usually lead to sufficient vitamin D synthesis. Individuals with limited sun exposure need to include good sources of vitamin D in their diet or take a supplement. It is important to note that the American Academy of Dermatology advises that photoprotective measures be taken, including the use of sunscreen, whenever one is exposed to the sun. Shereen A. Gharbia, PharmD

Q: I am 74 with a history of osteoporosis. I am 5 feet, 100lbs. I take 1200 mg calcium and 800 IU vitamin D. My doctor says to take 2000 IU vitamin D3. Is that too much vitamin D? Should I get calcium without vitamin D? I have stopped taking Fosamax after taking it for 10 plus years, because I was concerned about the side effects after taking the same medication for so long.

A: Osteoporosis is a common condition, with more than 25 million Americans affected. Although osteoporosis is most often associated with inadequate calcium intake, insufficient vitamin D contributes to osteoporosis because vitamin D is necessary to help the body absorb calcium. With appropriate levels of vitamin D, bone strength can be maintained and osteoporosis prevented in older adults, postmenopausal women, and people taking chronic corticosteroid therapy. According to the National Institutes of Health, the upper level of intake for women over the age of 14 years is 2,000 IU daily. Some studies have shown that levels as high as 10,000 IU daily do not cause harm; however, these studies may not have been designed to show long-term effects. Generally, the side effects of too much vitamin D include the nonspecific symptoms of nausea, vomiting, poor appetite, constipation, weakness, and weight loss. High levels of vitamin D can raise calcium levels in the blood and cause confusion and heart rhythm abnormalities. Your doctor can check your vitamin D and calcium levels by blood test to ensure that they do not increase beyond the normal levels. If you are concerned about your medications, please talk to your doctor for guidance based on your health status and current medications, particularly before taking any action. Michelle McDermott, PharmD

Q: My doctor told me to take vitamin D 5000IU, and I have for 7 months. I read later that it should be done for only 3 months and then down to 2000IU. Is this true? Lately I ache like I did on cholesterol medications and am wondering if it's because of too much vitamin D?

A: The National Osteoporosis Foundation recommends taking 400 IU to 800 IU of vitamin D daily for adults under age 50, and 800 IU to 1000 IU daily for older adults. People who have low levels of vitamin D may be instructed to take more by their physician. Your physician can perform a blood test to determine the proper dose of vitamin D depending on your vitamin D level. Excessive vitamin D intake may cause too much calcium in the blood (hypercalcemia). Symptoms of hypercalcemia include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, vomiting, abdominal cramps, constipation, diarrhea, dizziness, ringing in the ears, trouble walking, muscle pain, bone pain, and irritability. According to the Office of Dietary Supplements, some of the symptoms of too much vitamin D include: anorexia, weight loss, heart arrhythmias, and polyuria (large amount of urine with frequent urination). Research suggests that vitamin D may play a role in the prevention of more than just fractures. Vitamin D intake appears to decrease the risk of certain types of cancer. Early evidence suggests that diabetes, hypertension, cardiovascular disease, and multiple sclerosis may also be linked to low levels of vitamin D. Burton Dunaway, PharmD

Q: What are the effects of taking 50,000 units of vitamin D once weekly for 4 weeks?

A: Vitamin D is a fat-soluble vitamin that is needed for the proper absorption and function of calcium in the body. It is also important for the functioning of muscles, nerves, bones, and the immune system. Vitamin D is naturally found in very few foods, but can be found in fortified foods such as cereal or dairy products. The skin is able to synthesize or make vitamin D when it is exposed to sunlight. Whether vitamin D comes from food or is made by the skin, it must be activated in the body by the liver and kidneys. So, deficiencies can develop in people who do not get enough in their diet, who do not get adequate sun exposure, or who have organ disorders. Side effects are primarily related to getting too much vitamin D and it is possible to get too much vitamin D. This is more likely with long-term treatment. Short-term treatment (up to 8 weeks) with high doses (50,000 units per week) is unlikely to cause toxicity. Symptoms of too much vitamin D are nausea, vomiting, constipation, weakness, poor appetite, weight loss, muscle or bone pain, confusion, metallic taste in the mouth, itchy skin, headache, confusion, and changes in heart rate. Seek emergency medical attention if you are experiencing these symptoms or if you think you have taken too much vitamin D. Contact your doctor right away if you experience other side effects such as urinating more than usual, chest pain, shortness of breath, or changes in behavior. This is not a complete list of the risks and side effects that can occur with vitamin D. Sarah Lewis, PharmD

Q: Can vitamin D3 and/or Effexor XR cause abdominal bloating?

A: Vitamin D3 is a medication that is used to treat deficiency or help with calcium absorption in the treatment of osteoporosis. The prescribing information on vitamin D states that there is generally no side effects associated with the medication unless too much is taken. The side effects of too much vitamin D include weakness, sleepiness, dry mouth, headache, nausea, metallic taste and vomiting. Effexor XR (venlafaxine ER) is a medication that is used to treat depression and anxiety disorders. Effexor is in the class of medications called SNRIs that work by bringing a balance to the chemicals norepinephrine and serotonin in the brain that are causing your symptoms. The prescribing information on Effexor XR lists the following as common side effects of the medication: nausea, insomnia, appetite changes, drowsiness, dry mouth, increased sweating, constipation, abnormal dreams and weight gain/loss. The prescribing information on Effexor XR and Vitamin D do not specifically mention bloating as a side effect of the medications. Effexor XR can cause constipation or gas and these side effects may lead to the feeling of being bloated. If you are experiencing severe bloating where your stomach is distended often, you should consult with your physician to be sure there are no underlying conditions that may be causing this issue. Lori Poulin, PharmD

Q: What are the symptoms of vitamin D overdose?

A: Vitamin D is used by the body to help maintain strong bones, nerves, muscles and immune system. The daily recommended allowance of vitamin D is 400 IU per day. The upper limit of vitamin D that may be taken is 2000 IU per day. Anything beyond 2000 IU must be closely monitored by your physician and should not be taken unless directed. The early signs of vitamin D overdose include: weakness metallic taste in mouth weight loss muscle or bone pain constipation nausea and vomiting When you have too much vitamin D this can also cause an increase in calcium in the blood which may lead to the following symptoms: confusion disorientation problems with heart rhythm. Lori Poulin, PharmD

Q: I am supposed to take 2000 IU of vitamin D. Should I take vitamin D2 or vitamin D3?

A: Vitamin D is a fat-soluble vitamin that is not present in a lot of foods. Vitamin D is added to many foods and it is available as a dietary supplement. Vitamin D is required for calcium absorption and to help promote bone growth. Recent studies have found that vitamin D is important for proper functioning of the nerves, muscles, and immune system. Vitamin D is available in two forms, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). In the past, the two forms have been considered equivalent based on their ability to cure vitamin D deficiency that leads to brittle bones (or Rickets). Recent evidence suggests that the two forms of vitamin D are handled differently by the body and that vitamin D3 could be more than three times as effective as vitamin D2 in raising blood concentrations of the active form of vitamin D. However, other studies have directly compared the two forms of vitamin D and have found no differences in blood levels of the active form. Given this information, there is no evidence to clearly support the use of one form over the other. Many vitamin D supplements are available. Your healthcare provider can determine which form of vitamin D is right for you and then suggest an appropriate supplement based on your health status and current medications. Michelle McDermott, PharmD

Q: I am 64 years old and want to know how many milligrams of vitamin D I should take?

A: The National Institutes of Health (NIH) states that the best method to get an adequate intake of vitamins is to eat a balanced diet with a variety of foods. The United States Recommended Daily Allowance (U.S. RDA) for vitamin D, used to prevent osteoporosis, is 400 IU per day. In some cases, if the diet is not sufficient in providing the vital nutrient, a daily vitamin may be needed. Some of the vitamins, including vitamin D are fat soluble and an overdose can occur if too much is taken. Prescription doses used to treat deficiency often reach 50,000 IU per week. However, at these doses, patients are closely monitored by their doctor during treatment. Some foods can also provide vitamin D, such as oily fish (blue fish, salmon, and mackerel). Fortified milk and other dairy products are a good source of vitamin D. Vegetables do not provide significant amounts of vitamin D. Talk to your doctor to determine if supplementation with vitamin D is appropriate for you and what dose is required. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Patti Brown, PharmD

Q: Can I take calcium citrate or calcium carbonate with vitamin D if I take Drisdol once a month?

A: Drisdol (ergocalciferol or vitamin D2) is an important nutrient for the body. Vitamin D helps the body absorb calcium and grow healthy bones, and it reduces inflammation. Drisdol is used to treat vitamin D deficiencies, low phosphate levels, and decreased functioning of the parathyroid gland. The dosage of Drisdol that you receive is intended to treat the medical condition that you have. It is important to discuss all sources of vitamin D and other supplements, such as calcium, that you take with your healthcare provider to ensure that you do not get too much of any nutrient. High levels of vitamin D can cause nonspecific symptoms such as nausea, vomiting, poor appetite, constipation, weakness, and weight loss. In addition, too much vitamin D can increase the blood level of calcium, which may cause mental status changes like confusion, heart rhythm abnormalities, and increase the risk of kidney stones. For these reasons, it is best to first talk to your doctor before adding other supplements to your daily regimen. By looking at your blood levels of these nutrients, your doctor can determine if additional supplements are right for you and then suggest appropriate supplements. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Michelle McDermott, PharmD

Q: What is the correct amount of vitamin D a women should have? I am 52 years old.

A: Vitamin D is a fat-soluble vitamin that is found naturally in very few foods. It can be found in a variety of fortified foods, such as dairy, cereals, and orange juice, and it can be synthesized, or made by the skin, when it is exposed to sunlight. Whether from food or made by the skin, vitamin D must be activated first by the liver and then by the kidneys in order to work properly. Vitamin D is necessary for the proper absorption and function of calcium in the body. It is needed for proper growth and functioning of the bones, nerves, muscles, and immune system. According to the National Institutes of Health (NIH), the adequate intake of vitamin D for a woman aged 51 to 70 years is 400 IU. Deficiencies can develop in people who do not take in enough vitamin D in their diet, who do not get enough sun exposure, or who have liver or kidney problems. Consult with your doctor for specific vitamin D requirements or supplementation needs based on your specific circumstances. In general, vitamin and nutritional supplements should only be used under the supervision of your doctor. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications, particularly before taking any action. Sarah Lewis, PharmD

Q: What are the hazards of taking a vitamin D tablet with Lexapro, Wellbutrin, Chantix, and Buspar? Are there any advantages?

A: According to the prescribing information of all the medications you are taking, vitamin D is not listed as a supplement that may cause any drug interactions or any unwanted side effects. Vitamin D is a dietary supplement that can be found in small amounts in a few foods, including fatty fish, such as herring, mackerel, sardines and tuna. Vitamin D is sometimes added to dairy products, juices, and cereals. These food products will be marketed as fortified with vitamin D. However, most vitamin D, 80 to 90 percent of what the body gets, is obtained through exposure to sunlight. Vitamin D can also be made in the laboratory as medicine. According to the National Institutes of Health (NIH), some benefits of using Vitamin D include preventing and treating rickets, a disease that is caused by not having enough vitamin D. Vitamin D is also used for treating loss of bone density (osteoporosis), softening of the bones (osteomalacia), bone loss in people with a condition called hyperparathyroidism, and an inherited disease called osteogenesis imperfecta, in which the bones are especially brittle and easily broken. It is also used for preventing falls and fractures in people at risk for osteoporosis, and preventing low calcium and bone loss in people with kidney failure. The use of vitamin D is likely safe when taken by mouth in recommended dosages. Most people do not commonly experience side effects associated with vitamin D, unless it is overused and too much is taken. Some of the side effects associated with taking too much vitamin D include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, vomiting, and others. When taking vitamin D for long periods of time, with high doses such as 50 mcg (2000 units) per day, it is possibly unsafe and may cause excessively high levels of calcium in the blood. However, certain higher doses are often needed for the short-term treatment of vitamin D deficiency. Vitamin deficiency treatment should be done under the supervision of a healthcare provider. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Anissa Lee, RPh

Q: I live in Europe and we use micrograms as a measurement for vitamin D. How much is a microgram compared to an international unit? My dose is 20 micrograms a day. Is that enough vitamin D?

A: To convert micrograms into international units (IU), simply multiply the micrograms by 40. Thus, your dose of vitamin D at 20 micrograms per day is equivalent to 800 IU of vitamin D. This is a standard dose of vitamin D and should be sufficient to meet your daily needs, as long as you are not vitamin D deficient. It is recommended that you speak with your healthcare provider to determine the exact amount of vitamin D that you should be taking. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Megan Uehara, PharmD

Q: My vitamin D level was checked and was very low. My doctor started me on prescription vitamin D twice weekly. I have noticed my hair is falling out badly. Could this be from taking such a high amount of vitamin D?

A: Vitamin D is an essential vitamin with many functions in the human body. It helps the body absorb calcium and grow healthy bones and it reduces inflammation. Current research has shown that vitamin D is also involved in cell growth and differentiation, cell death, and blood vessel generation. Unfortunately, vitamin D is not found naturally in a lot of foods. The best sources are fatty fish, including salmon, tuna, and mackerel. Fortified foods, such as milk, provide most of the vitamin D in American diets. Vitamin D is made in our bodies when our skin is exposed to ultraviolet rays from the sun.

Q: My primary care physician prescribed vitamin D 50,000 IU per week for my deficiency. My endocrinologist increased that to 100,000 IU per week. Is 100,000 IU too much? I am afraid that this might be toxic and cause more problems. I had bariatric surgery almost two years ago, which is probably why I have the vitamin D deficiency.

A: Vitamin D is an essential vitamin that helps the body absorb calcium and grow healthy bones. Research has also shown that vitamin D is helpful in reducing inflammation, generating new blood vessels, and promoting cell growth and differentiation. For people who have undergone gastric bypass surgery, the absorption of vitamin D may be reduced because the part of the upper small intestine where vitamin D is absorbed was surgically bypassed as part of the procedure. The dosage of vitamin D used to treat a deficiency varies depending on many patient-specific factors. According to the National Institutes of Health (NIH), a large dose of vitamin D such as 50,000 IU/week for a short period of time (such as eight weeks) is not associated with side effects. Excess vitamin D is stored and used as needed to maintain normal blood levels. In addition, several more recent studies support the use of higher dosages of vitamin D, including those up to 10,000 IU/day (about 70,000 IU/week). The side effects of too much vitamin D include nonspecific symptoms such as nausea, vomiting, poor appetite, constipation, weakness, and weight loss. High blood levels of vitamin D can also increase blood levels of calcium, leading to some more serious side effects including confusion, heart rhythm abnormalities, and kidney stones. Studies also suggest that toxicity can be determined by blood levels of vitamin D, with levels greater than 200 ng/mL being considered possibly toxic. Routine monitoring of blood levels is recommended during replacement therapy. If you think you are experiencing a side effect, or a new symptom develops, it is always best to talk to your doctor before taking any action. Do not stop or change your medications without the guidance of your doctor. Your health care provider can give you guidance based on your health status and current medications. Michelle McDermott, PharmD

Q: Can stress or depression cause vitamin D levels to drop?

A: Vitamin D is classified as a fat soluble vitamin. Vitamin D is produced by the body when exposed to sunlight. Vitamin D can also be obtained in small amounts through the diet and can be taken as a supplement. Some foods are fortified with vitamin D. According to the National Institutes of Health (NIH), vitamin D has many uses in the body. Vitamin D has been in the news and media quite a bit recently as experts are finding more and more theoretical benefits of this vitamin. There are several causes of low vitamin D levels. Some of the causes of low vitamin D levels include not getting enough sunlight (such as individuals that live in the northern United States and Canada), patients that either cover up or consistently use sun block when exposed to sunlight. Older individuals have an increased risk of low levels of vitamin D due to less receptors in the skin that are responsible for the conversion of sunlight into vitamin D, less time spent in the sun, lack of vitamin D in their diet, difficulty absorbing vitamin D, or problems with converting vitamin D to the active form as a result of aging kidneys. Some scientists have theories that low vitamin D levels may lead to disturbances in mood. According to medical sources, there is evidence that suggests that Vitamin D supplementation may help with mood. However, this evidence is not conclusive and the authors of the studies conclude that additional studies need to be performed to fully understand this possible connection. Have your vitamin D levels checked if they haven't been already. If vitamin D levels are low, then your physician will likely recommend vitamin D supplementation. Consult with your physician regarding the appropriate dosage. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Jen Marsico, RPh

Q: I take a one-a-day multivitamin for women and additional vitamin D as well. Is this too much vitamin D?

A: Vitamin D is classified as a fat soluble vitamin. Vitamin D is produced by the body when exposed to sunlight. Vitamin D can also be obtained in small amounts through the diet and can be taken as a supplement. Some foods, such as certain cereals, are fortified with vitamin D. According to the National Institutes of Health (NIH), vitamin D has many uses in the body. Vitamin D has been in the news and media recently as experts are finding more and more theoretical benefits of this vitamin. The best way to determine if you need supplemental vitamin D is to have your physician perform lab tests to determine your current vitamin D level. Depending on your current level, your physician can recommend an appropriate dosage for you. Recently, the dosing of vitamin D has been somewhat controversial. However, according to the National Institutes of Health (NIH), the recommended adequate intake (AI) for vitamin D for a 58 year old female patient is 10 mcg or 400 IU. Adequate intake is defined as the value that is assigned to a supplement when there is not enough evidence to assign a recommended dietary allowance (RDA). The AI for vitamin D stands for the daily intake of the vitamin that is required for maintenance of healthy bones and for normal metabolism of calcium in healthy individuals. The AI recommendations are based on the assumption that vitamin D is not being synthesized by sunlight exposure. The intake reference for vitamins and nutrients is developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies. Consult with your physician regarding the vitamin D intake that best meets your needs. Your physician can perform blood tests to determine what amount of vitamin D is appropriate for you. Generally speaking, over-the-counter supplements, such as vitamin D, should only be taken if they are approved by your physician. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Jen Marsico, RPh

Q: What causes low vitamin D levels?

A: Vitamin D is a fat soluble vitamin that is found naturally in very few foods. Food sources of vitamin D include fish, such as tuna, salmon, and mackerel, and fortified foods, such as dairy products including milk, yogurt, and cheese. The skin is also able to synthesize, or make, vitamin D when it is exposed to sunlight. Either way, vitamin D must be metabolized or activated in the body, first by the liver and then by the kidneys. Deficiencies in vitamin D can result from inadequate dietary intake, inadequate exposure to sunlight, or liver or kidney disease. Your doctor is best able to properly evaluate your medical condition, diagnose the underlying cause of your low vitamin D levels and make recommendations based on your specific circumstances. If you have concerns about low vitamin D levels, consult with your doctor. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications, particularly before taking any action. Sarah Lewis, PharmD

Q: Can too much vitamin D cause joint pain?

A: Vitamin D is a fat soluble vitamin that is found naturally in very few foods. Vitamin D is added to many fortified foods, such as dairy products (milk, cheese, yogurt), juices, and whole grain products (cereals, breads). The skin is also able to synthesize, or make, vitamin D when it is exposed to sunlight. Either way, vitamin D must be activated in the body, first by the liver and then by the kidneys. Deficiencies can develop when people do not get enough vitamin D in the diet, do not get enough sun exposure, or have liver or kidney disease. According to the National Institutes of Health (NIH), the adequate daily intake for a woman between the ages of 19 and 50 years is 200 IU. It is possible to get too much vitamin D. Symptoms of too much vitamin D include nausea, vomiting, poor appetite, constipation, weight loss, headache, weakness, drowsiness, muscle or bone pain, confusion, and abnormal heart beats. If you think you have taken too much vitamin D, seek emergency medical attention. A vitamin D overdose can be life-threatening. This is not a complete list of side effects or risks associated with vitamin D. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications, particularly before taking any action. Sarah Lewis, PharmD

Q: I am 58 years old. I have been taking 50,000 IU of vitamin D. Can I have side effects from this?

A: Vitamin D is a fat soluble vitamin. An excessive intake of vitamin D can cause unwanted side effects including nausea, vomiting, constipation, and weakness. An excessive intake of vitamin D can also affect calcium levels causing other dangerous side effects. Vitamin D is important for the absorption of calcium from the stomach and for proper functioning of calcium in the body. The Recommended Dietary Allowance (RDA) for vitamin D is currently 400 IU for patients between 50 and 70 years of age. 50,000 IU is the prescription dose of vitamin D. According to the U.S. Food and Drug Administration (FDA), this is an approved dose for the treatment of certain conditions. Supplementation with vitamin D is extremely patient specific and depends on various factors including diet, lifestyle, medical and prescription history and individual risk factors. It is important for your doctor to do routine monitoring while being treated with vitamin D. You may want to contact your health care provider to determine the appropriate intake of vitamin D recommended based on your specific needs. It is always important to check with your doctor before taking any vitamins, supplements or over-the-counter products. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Beth Isaac, PharmD

Q: Can vitamin D cause constipation?

A: According to the National Institutes of Health, Office of Dietary Supplements (ODS), constipation is one of the signs of toxicity from vitamin D. There can be many underlying factors that can lead to constipation. Please consult with your health care provider in regards to the symptoms of constipation you are experiencing. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD

Q: What is the recommended dose of vitamin D?

A: According to the Office of Dietary Supplements (ODS), the recommended daily intake of vitamin D for an adult 19 to 70 years old is 600 IU. The need for vitamin supplementation and the choice of the most appropriate vitamin preparation and dose may depend on many patient specific characteristics. Thus, it is important to consult with your physician regarding the appropriate intake of vitamin D that best meets your individual needs. Vitamin D is important for the absorption of calcium from the stomach and for the proper functioning of calcium in the body. Vitamin D is used to treat hypoparathyroidism (decreased functioning of the parathyroid glands), rickets (softening of the bones caused by a vitamin D deficiency) and hypophosphatemia (low phosphate levels in the blood). Vitamin D may also be used to treat other conditions as determined by your health care provider. Vitamin D is a fat soluble vitamin and an excessive intake can cause unwanted side effects. An excessive intake of vitamin D can cause side effects including nausea, vomiting, constipation and weakness and can affect calcium levels causing other dangerous side effects. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD