{{Short description|Vitamin D2, a chemical compound}} {{Use dmy dates|date=October 2022}} {{cs1 config |name-list-style=vanc |display-authors=6}} {{Infobox drug | image = Ergocalciferol.svg | image_class = skin-invert-image | width = | alt = Skeletal formula of ergocalciferol | image2 = Ergocalciferol 3D ball.png | image_class2 = bg-transparent | width2 = | alt2 = Ball-and-stick model of the ergocalciferol molecule | caption =
<!-- Clinical data --> | pronounce = | tradename = Drisdol, Calcidol, others | Drugs.com = {{Drugs.com|monograph|ergocalciferol}} | MedlinePlus = a616042 | DailyMedID = Ergocalciferol | pregnancy_AU = <!-- A / B1 / B2 / B3 / C / D / X --> | pregnancy_AU_comment = | pregnancy_category = | routes_of_administration = By mouth, intramuscular | class = | ATC_prefix = A11 | ATC_suffix = CC01 | ATC_supplemental =
<!-- Legal status --> | legal_AU = <!-- S2, S3, S4, S5, S6, S7, S8, S9 or Unscheduled --> | legal_AU_comment = | legal_BR = <!-- OTC, A1, A2, A3, B1, B2, C1, C2, C3, C4, C5, D1, D2, E, F --> | legal_BR_comment = | legal_CA = Rx-only | legal_CA_comment = <ref>{{cite web | title=Summary Basis of Decision (SBD) for Rayaldee | website=Health Canada | date=23 October 2014 | url=https://hpr-rps.hres.ca/reg-content/summary-basis-decision-detailTwo.php?linkID=SBD00409&lang=en | access-date=29 May 2022 | archive-date=31 May 2022 | archive-url=https://web.archive.org/web/20220531071351/https://hpr-rps.hres.ca/reg-content/summary-basis-decision-detailTwo.php?linkID=SBD00409&lang=en | url-status=live }}</ref> | legal_DE = <!-- Anlage I, II, III or Unscheduled --> | legal_DE_comment = | legal_NZ = <!-- Class A, B, C --> | legal_NZ_comment = | legal_UK = POM | legal_UK_comment = <ref>{{cite web | title=Ergocalciferol Injection BP 300,000IU - Summary of Product Characteristics (SmPC) | website=(emc) | date=8 July 2020 | url=https://www.medicines.org.uk/emc/product/9133/smpc | access-date=10 June 2022 | archive-date=19 January 2021 | archive-url=https://web.archive.org/web/20210119095620/https://www.medicines.org.uk/emc/product/9133/smpc | url-status=live }}</ref> | legal_US = OTC | legal_US_comment = / Rx-only | legal_EU = | legal_EU_comment = | legal_UN = <!-- N I, II, III, IV / P I, II, III, IV --> | legal_UN_comment = | legal_status = <!-- For countries not listed above -->
<!-- Pharmacokinetic data --> | bioavailability = | protein_bound = | metabolism = | metabolites = | onset = | elimination_half-life = | duration_of_action = | excretion =
<!-- Identifiers --> | CAS_number = 50-14-6 | PubChem = 5280793 | IUPHAR_ligand = | DrugBank = DB00153 | ChemSpiderID = 4444351 | UNII = VS041H42XC | KEGG = C05441 | ChEBI = 28934 | ChEMBL = 1536 | NIAID_ChemDB = | PDB_ligand = | synonyms = vitamin D<sub>2</sub>
<!-- Chemical and physical data --> | IUPAC_name = (3''S'',5''Z'',7''E'',22''E'')-9,10-secoergosta-5,7,10(19),22-tetraen-3-ol | C = 28 | H = 44 | O = 1 | SMILES = O[C@@H]1CC(\C(=C)CC1)=C\C=C2/CCC[C@]3([C@H]2CC[C@@H]3[C@@H](/C=C/[C@H](C)C(C)C)C)C | StdInChI = 1S/C28H44O/c1-19(2)20(3)9-10-22(5)26-15-16-27-23(8-7-17-28(26,27)6)12-13-24-18-25(29)14-11-21(24)4/h9-10,12-13,19-20,22,25-27,29H,4,7-8,11,14-18H2,1-3,5-6H3/b10-9+,23-12+,24-13-/t20-,22+,25-,26+,27-,28+/m0/s1 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI_comment = | StdInChIKey = MECHNRXZTMCUDQ-RKHKHRCZSA-N | density = | density_notes = | melting_point = 114 | melting_high = 118 | melting_notes = | boiling_point = | boiling_notes = | solubility = | sol_units = | specific_rotation = }}
<!-- Definition and medical uses --> '''Ergocalciferol''', also known as '''vitamin D<sub>2</sub>''' and nonspecifically '''calciferol''', is a type of vitamin D found in food. It is used as a dietary supplement<ref>{{cite book| vauthors = Coulston AM, Boushey C, Ferruzzi M |title=Nutrition in the Prevention and Treatment of Disease|date=2013|publisher=Academic Press|isbn=9780123918840|page=818|url=https://books.google.com/books?id=pmapb3rvzpYC&pg=PA818 | url-status=live|archive-url=https://web.archive.org/web/20161230000458/https://books.google.ca/books?id=pmapb3rvzpYC&pg=PA818|archive-date=30 December 2016}}</ref> to prevent and treat vitamin D deficiency<ref name=BNF69/> due to poor absorption by the intestines or liver disease.<ref name=WHO2008/> It may also be used for low blood calcium due to hypoparathyroidism.<ref name=WHO2008/> It is taken by mouth or via injection into a muscle.<ref name=BNF69>{{cite book|title=British national formulary : BNF 69|date=2015|publisher=British Medical Association|isbn=9780857111562|pages=703–704|edition=69}}</ref><ref name=WHO2008>{{cite book | title = WHO Model Formulary 2008 | year = 2009 | isbn = 9789241547659 | vauthors = ((World Health Organization)) | veditors = Stuart MC, Kouimtzi M, Hill SR | hdl = 10665/44053 | author-link = World Health Organization | publisher = World Health Organization | hdl-access=free |page=498 }}</ref>
<!-- Side effects and mechanism --> Excessive doses can result in vitamin D toxicity causing increased urine production, high blood pressure, kidney stones, kidney failure, muscle weakness, and constipation.<ref name=AHFS2016>{{cite web|title=Ergocalciferol|url=https://www.drugs.com/monograph/ergocalciferol.html|publisher=The American Society of Health-System Pharmacists|access-date=8 December 2016|url-status=live|archive-url=https://web.archive.org/web/20161230002716/https://www.drugs.com/monograph/ergocalciferol.html|archive-date=30 December 2016}}</ref> If high doses are taken for a long period of time, tissue calcification may occur.<ref name=WHO2008/> Normal doses are safe in pregnancy.<ref name=Ric2015>{{cite book| vauthors = Hamilton R |title=Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition|date=2015|publisher=Jones & Bartlett Learning|isbn=9781284057560|page=227}}</ref> It works by increasing the amount of calcium absorbed by the intestines and reabsorbed by the kidneys.<ref name=AHFS2016/> Food in which it is found include some mushrooms.<ref name=NIH2016>{{cite web|title=Office of Dietary Supplements - Vitamin D|url=https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/|website=ods.od.nih.gov|access-date=30 December 2016|date=11 February 2016|url-status=live|archive-url=https://web.archive.org/web/20161231073744/https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/|archive-date=31 December 2016}}</ref>
<!-- History and culture --> Ergocalciferol was first described in 1936.<ref name=Fis2006>{{cite book| vauthors = Fischer J, Ganellin CR |title=Analogue-based Drug Discovery|date=2006|publisher=John Wiley & Sons|isbn=9783527607495|page=451|url=https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA451 | url-status=live|archive-url=https://web.archive.org/web/20161230085612/https://books.google.ca/books?id=FjKfqkaKkAAC&pg=PA451|archive-date=30 December 2016}}</ref> Ergocalciferol is available as a generic medication and over the counter.<ref name=AHFS2016/> In 2023, it was the 48th most commonly prescribed medication in the United States, with more than 13{{nbsp}}million prescriptions.<ref name="Top300Drugs">{{cite web | title=Top 300 of 2023 | url=https://clincalc.com/DrugStats/Top300Drugs.aspx | website=ClinCalc | access-date=12 August 2025 | archive-date=12 August 2025 | archive-url=https://web.archive.org/web/20250812130026/https://clincalc.com/DrugStats/Top300Drugs.aspx | url-status=live }}</ref><ref>{{cite web | title = Ergocalciferol Drug Usage Statistics, United States, 2014 - 2023 | website = ClinCalc | url = https://clincalc.com/DrugStats/Drugs/Ergocalciferol | access-date = 18 August 2025 }}</ref> Certain foods such as breakfast cereal and margarine have ergocalciferol added to them in some countries.<ref>{{cite book | vauthors = Feral P, Hall L |title=Dining with Friends: The Art of North American Vegan Cuisine|date=2005|publisher=Friends of Animals/Nectar Bat Press|isbn=9780976915904|page=[https://archive.org/details/diningwithfriend0000fera/page/160 160]|url=https://archive.org/details/diningwithfriend0000fera |url-access=registration }}</ref><ref>{{cite book | vauthors = Bennett B, Sammartano R |title= The Complete Idiot's Guide to Vegan Living | edition = Second |date=2012|publisher=Penguin|isbn=9781615642793|page=Chapter 15|url=https://books.google.com/books?id=MbzIcj32RzEC&pg=PT215 | url-status=live|archive-url=https://web.archive.org/web/20161230230633/https://books.google.ca/books?id=MbzIcj32RzEC&pg=PT215|archive-date=30 December 2016}}</ref> It is on the World Health Organization's List of Essential Medicines.<ref name="WHO23rd">{{cite book | vauthors = ((World Health Organization)) | title = The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023) | year = 2023 | hdl = 10665/371090 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MHP/HPS/EML/2023.02 | hdl-access=free }}</ref>
==Use== thumb|Vitamin D<sub>2</sub> supplements Ergocalciferol may be used as a vitamin D supplement, whereas cholecalciferol (vitamin D<sub>3</sub>) is produced naturally by the skin when exposed to ultraviolet light.<ref name="holick guideline">{{cite journal | vauthors = Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM | display-authors = 6 | title = Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 96 | issue = 7 | pages = 1911–1930 | date = July 2011 | pmid = 21646368 | doi = 10.1210/jc.2011-0385 | doi-access = free }}</ref> Ergocalciferol (D<sub>2</sub>) and cholecalciferol (D<sub>3</sub>) are considered to be equivalent for vitamin D production, as both forms appear to have similar efficacy in ameliorating rickets<ref>{{cite journal | vauthors = Thacher TD, Fischer PR, Obadofin MO, Levine MA, Singh RJ, Pettifor JM | title = Comparison of metabolism of vitamins D2 and D3 in children with nutritional rickets | journal = Journal of Bone and Mineral Research | volume = 25 | issue = 9 | pages = 1988–1995 | date = September 2010 | pmid = 20499377 | pmc = 3153403 | doi = 10.1002/jbmr.99 }}</ref> and reducing the incidence of falls in elderly patients.<ref>{{cite journal | vauthors = Fosnight SM, Zafirau WJ, Hazelett SE | title = Vitamin D supplementation to prevent falls in the elderly: evidence and practical considerations | journal = Pharmacotherapy | volume = 28 | issue = 2 | pages = 225–234 | date = February 2008 | pmid = 18225968 | doi = 10.1592/phco.28.2.225 | s2cid = 37034292 | doi-access = free }}</ref> Conflicting reports exist, however, concerning the relative effectiveness, with some studies suggesting that ergocalciferol has less efficacy based on limitations in absorption, binding, and inactivation.<ref name="ajcn">{{cite journal | vauthors = Tripkovic L, Lambert H, Hart K, Smith CP, Bucca G, Penson S, Chope G, Hyppönen E, Berry J, Vieth R, Lanham-New S | display-authors = 6 | title = Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis | journal = The American Journal of Clinical Nutrition | volume = 95 | issue = 6 | pages = 1357–1364 | date = June 2012 | pmid = 22552031 | pmc = 3349454 | doi = 10.3945/ajcn.111.031070 }}</ref> A meta-analysis concluded that evidence usually favors cholecalciferol in raising vitamin D levels in blood, although it stated more research is needed.<ref name=ajcn/>
==Mechanism== Ergocalciferol is a secosteroid formed by a photochemical bond breaking of a steroid, specifically, by the action of ultraviolet light (UV-B or UV-C) on ergosterol, a form of provitamin D<sub>2</sub>.<ref name=pmid30322118>{{cite journal | vauthors = Cardwell G, Bornman JF, James AP, Black LJ | title = A Review of Mushrooms as a Potential Source of Dietary Vitamin D | journal = Nutrients | volume = 10 | issue = 10 | page = 1498 | date = October 2018 | pmid = 30322118 | pmc = 6213178 | doi = 10.3390/nu10101498 | doi-access = free }}</ref>
Like cholecalciferol, ergocalciferol is inactive by itself. It requires two hydroxylations to become active: the first in the liver by CYP2R1 to form 25-hydroxyergocalciferol (ercalcidiol or 25-OH D<sub>2</sub><ref>{{cite journal | vauthors = Suda T, DeLuca HF, Schnoes H, Blunt JW | title = 25-hydroxyergocalciferol: a biologically active metabolite of vitamin D2 | journal = Biochemical and Biophysical Research Communications | volume = 35 | issue = 2 | pages = 182–185 | date = April 1969 | pmid = 5305760 | doi = 10.1016/0006-291X(69)90264-2 }}</ref>), and the second in the kidney by CYP27B1, to form the active 1,25-dihydroxyergocalciferol (ercalcitriol or 1,25-(OH)<sub>2</sub>D<sub>2</sub>), which activates the vitamin D receptor.<ref>{{cite journal | vauthors = | title = IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN): Nomenclature of vitamin D. Recommendations 1981 | journal = European Journal of Biochemistry | volume = 124 | issue = 2 | pages = 223–227 | date = May 1982 | pmid = 7094913 | doi = 10.1111/j.1432-1033.1982.tb06581.x | doi-access = free }}</ref> Unlike cholecalciferol, 25-hydroxylation is not performed by CYP27A1 for ergocalciferol.<ref name=Bikle/>
Ergocalciferol and metabolites have lower affinity to the vitamin D-binding protein compared to the D<sub>3</sub> counterparts. The binding affinity of ercalcitriol to the vitamin D receptor is similar to that of calcitriol.<ref name=Bikle>{{cite journal | vauthors = Bikle DD | title = Vitamin D metabolism, mechanism of action, and clinical applications | journal = Chemistry & Biology | volume = 21 | issue = 3 | pages = 319–329 | date = March 2014 | pmid = 24529992 | pmc = 3968073 | doi = 10.1016/j.chembiol.2013.12.016 }}</ref> Ergocalciferol itself and metabolites can be deactivated by 24-hydroxylation.<ref>{{cite journal | vauthors = Houghton LA, Vieth R | title = The case against ergocalciferol (vitamin D2) as a vitamin supplement | journal = The American Journal of Clinical Nutrition | volume = 84 | issue = 4 | pages = 694–697 | date = October 2006 | pmid = 17023693 | doi = 10.1093/ajcn/84.4.694 | doi-access = free }}</ref>
==Sources== '''Fungus''', from USDA nutrient database (per 100g), D<sub>2</sub> + D<sub>3</sub>:<ref>{{cite web |url=http://www.nal.usda.gov/fnic/foodcomp/search/index.html |title=USDA nutrient database – ''use the keyword 'portabello' and then click submit'' |url-status=dead |archive-url=https://web.archive.org/web/20150222164135/http://www.nal.usda.gov/fnic/foodcomp/search/index.html |archive-date=22 February 2015 }}</ref><ref name=Haytowitz-USDA>{{cite web|author=Haytowitz DB|title=Vitamin D in mushrooms|url=https://www.ars.usda.gov/ARSUserFiles/80400525/Articles/AICR09_Mushroom_VitD.pdf|publisher=Nutrient Data Laboratory, US Department of Agriculture|access-date=16 April 2018|date=2009|archive-date=1 February 2021|archive-url=https://web.archive.org/web/20210201181749/https://www.ars.usda.gov/ARSUserFiles/80400525/Articles/AICR09_Mushroom_VitD.pdf|url-status=live}}</ref> * Mushrooms, ''Agaricus bisporus'': ** raw portobello: 0.3 μg (10 IU); exposed to ultraviolet light: 11.2 μg (446 IU) ** raw crimini: 0.1 μg (3 IU); exposed to ultraviolet light: 31.9 μg (1276 IU) * Mushrooms, shiitake: ** raw: Vitamin D (D<sub>2</sub> + D<sub>3</sub>): 0.4 μg (18 IU) ** dried: Vitamin D (D<sub>2</sub> + D<sub>3</sub>): 3.9 μg (154 IU)
'''Lichen''' * ''Cladina arbuscula'' specimens grown under different natural conditions contain provitamin D<sub>2</sub> and vitamin D<sub>2</sub>, ranges 89–146 and 0.22–0.55 μg/g dry matter respectively. They also contain vitamin D<sub>3</sub> (range 0.67 to 2.04 μg/g) although provitamin D<sub>3</sub> could not be detected. Vitamin D levels correlate positively with UV irradiation.<ref name="pmid11693362"/>
'''Plantae''' * Alfalfa (''Medicago sativa'' subsp. sativa), shoot: 4.8 μg (192 IU) vitamin D<sub>2</sub>, 0.1 μg (4 IU) vitamin D<sub>3</sub><ref>{{cite web |url=http://sun.ars-grin.gov:8080/npgspub/xsql/duke/plantdisp.xsql?taxon=606 |title=Dr. Duke's Phytochemical and Ethnobotanical Databases |url-status=dead |archive-url=https://web.archive.org/web/20151016051622/http://sun.ars-grin.gov:8080/npgspub/xsql/duke/plantdisp.xsql?taxon=606 |archive-date=16 October 2015 }}</ref>
=== Biosynthesis === <!-- Principle --> The vitamin D<sub>2</sub> content in mushrooms and ''C. arbuscula'' increase with exposure to ultraviolet light.<ref name="pmid11693362">{{cite journal | vauthors = Wang T, Bengtsson G, Kärnefelt I, Björn LO | title = Provitamins and vitamins D<sub>2</sub> and D<sub>3</sub> in Cladina spp. over a latitudinal gradient: possible correlation with UV levels | journal = Journal of Photochemistry and Photobiology B: Biology | volume = 62 | issue = 1–2 | pages = 118–122 | date = September 2001 | pmid = 11693362 | doi = 10.1016/S1011-1344(01)00160-9 | url = http://lup.lub.lu.se/record/133512 | access-date = 27 January 2019 | url-status = live | archive-url = https://web.archive.org/web/20200528231009/https://lup.lub.lu.se/search/publication/133512 | archive-date = 28 May 2020 }}</ref><ref name=usda-mush-light>{{cite web|author=Haytowitz DB|title=Vitamin D in mushrooms|url=https://www.ars.usda.gov/ARSUserFiles/80400525/Articles/AICR09_Mushroom_VitD.pdf|publisher=Nutrient Data Laboratory, US Department of Agriculture|access-date=16 April 2018|date=2009|archive-date=1 February 2021|archive-url=https://web.archive.org/web/20210201181749/https://www.ars.usda.gov/ARSUserFiles/80400525/Articles/AICR09_Mushroom_VitD.pdf|url-status=live}}</ref> Ergosterol (provitamin D<sub>2</sub>) found in these fungi is converted to {{ill|Previtamin D2|lt=previtamin D<sub>2</sub>|qid=Q76399730|s=1}} on UV exposure, which then turns into vitamin D<sub>2</sub>. As cultured mushrooms are generally grown in darkness, less vitamin D<sub>2</sub> is found compared to those grown in the wild or dried in the sun.<ref name=pmid30322118/>
<!-- Application --> When fresh mushrooms or dried powders are purposely exposed to ultraviolet light, vitamin D<sub>2</sub> levels can be concentrated to much higher levels.<ref name="keegan">{{cite journal | vauthors = Keegan RJ, Lu Z, Bogusz JM, Williams JE, Holick MF | title = Photobiology of vitamin D in mushrooms and its bioavailability in humans | journal = Dermato-Endocrinology | volume = 5 | issue = 1 | pages = 165–176 | date = January 2013 | pmid = 24494050 | pmc = 3897585 | doi = 10.4161/derm.23321 }}</ref><ref name=msnbc/><ref name="simon">{{cite journal | vauthors = Simon RR, Borzelleca JF, DeLuca HF, Weaver CM | title = Safety assessment of the post-harvest treatment of button mushrooms (Agaricus bisporus) using ultraviolet light | journal = Food and Chemical Toxicology | volume = 56 | pages = 278–289 | date = June 2013 | pmid = 23485617 | doi = 10.1016/j.fct.2013.02.009 }}</ref> The irradiation procedure does not cause significant discoloration, or whitening, of mushrooms.<ref>{{cite journal | vauthors = Koyyalamudi SR, Jeong SC, Song CH, Cho KY, Pang G | title = Vitamin D2 formation and bioavailability from Agaricus bisporus button mushrooms treated with ultraviolet irradiation | journal = Journal of Agricultural and Food Chemistry | volume = 57 | issue = 8 | pages = 3351–3355 | date = April 2009 | pmid = 19281276 | doi = 10.1021/jf803908q | bibcode = 2009JAFC...57.3351K }}</ref> Claims have been made that a normal serving (approx. 2 oz or 60 grams) of fresh mushrooms treated with ultraviolet light have increased vitamin D content to levels up to 80 micrograms or 3200 IU if exposed to just five minutes of UV light after being harvested.<ref name="msnbc">{{Cite news |title=Bringing Mushrooms Out of the Dark |date=18 April 2006 |url=http://www.nbcnews.com/id/12370708 |work=NBC News |access-date=6 August 2007 |archive-date=7 November 2017 |archive-url=https://web.archive.org/web/20171107112253/http://www.nbcnews.com/id/12370708 |url-status=dead }}</ref>
<!-- Effect on humans --> Button mushrooms with enhanced vitamin D<sub>2</sub> content produced this way functions similarly to a vitamin D<sub>2</sub> supplement; both effectively improves vitamin D status.<ref name=keegan/><ref name="pmid21540874">{{cite journal | vauthors = Urbain P, Singler F, Ihorst G, Biesalski HK, Bertz H | title = Bioavailability of vitamin D₂ from UV-B-irradiated button mushrooms in healthy adults deficient in serum 25-hydroxyvitamin D: a randomized controlled trial | journal = European Journal of Clinical Nutrition | volume = 65 | issue = 8 | pages = 965–971 | date = August 2011 | pmid = 21540874 | doi = 10.1038/ejcn.2011.53 | doi-access = free }}</ref> Vitamin D<sub>2</sub> from UV-irradiated yeast baked into bread or mushrooms is bioavailable and increases blood levels of 25(OH)D.<ref name=keegan/>
==Names== Viosterol, the name given to early preparations of irradiated ergosterol, is essentially synonymous with ergocalciferol.<ref>{{cite journal | date = 1930 | title = Viosterol official name for irradiated ergosterol | journal = Journal of Chemical Education | volume = 7 | issue = 1 | pages = 166 | doi = 10.1021/ed007p166 | last1 = Science Service | bibcode = 1930JChEd...7..166S }}</ref><ref>See "Viosterol" and "Calciferol" at Merriam-Webster Medical Dictionary, e.g., {{cite web |url=http://www.merriam-webster.com/medical/viosterol |title=Medical Definition of VIOSTEROL |access-date=10 July 2014 |url-status=live |archive-url=https://web.archive.org/web/20140714154919/http://www.merriam-webster.com/medical/viosterol |archive-date=14 July 2014 }} and {{cite web |url=http://www.merriam-webster.com/medical/calciferol |title=Definition of CALCIFEROL |access-date=10 July 2014 |url-status=live |archive-url=https://web.archive.org/web/20140714212827/http://www.merriam-webster.com/medical/calciferol |archive-date=14 July 2014 }}, accessed 10 July 2014.</ref> However, currently, Viosterol is also the brand name for cholecalciferol (vitamin D<sub>3</sub>) in some countries.<ref>{{cite web |url=https://www.vademecum.es/equivalencia-lista-viosterol+comprimido+5000+ui-uruguay-a11cc05--uy_1 |title=Viosterol comprimido 5000 UI |access-date=5 September 2022 |archive-date=5 September 2022 |archive-url=https://web.archive.org/web/20220905231617/https://www.vademecum.es/equivalencia-lista-viosterol+comprimido+5000+ui-uruguay-a11cc05--uy_1 |url-status=dead }}</ref><ref>{{cite web |url=https://www-eticos-com-py.translate.goog//producto/247/viosterol-1000?_x_tr_sch=http&_x_tr_sl=es&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp |title=Viosterol 1000 |access-date=6 September 2022 |archive-date=6 September 2022 |archive-url=https://web.archive.org/web/20220906000655/https://www-eticos-com-py.translate.goog//producto/247/viosterol-1000?_x_tr_sch=http&_x_tr_sl=es&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp |url-status=dead }}</ref>
Ergocalciferol is manufactured and sold under various brand names, including Deltalin (Eli Lilly and Company), Drisdol (Sanofi-Synthelabo), and Calcidol (Patrin Pharma).{{citation needed|date=August 2024}}
== References == {{reflist}}
== External links == * [https://webbook.nist.gov/cgi/cbook.cgi?ID=C50146 NIST Chemistry WebBook page for ergocalciferol]
{{Vitamins}} {{Sterols}} {{Vitamin D receptor modulators}} {{Cholesterol metabolism intermediates}} {{Portal bar | Medicine}} {{Authority control}}
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