
Vitamin D2 (Ergocalciferol)Benefits, Dosage & Interactions
Also known as: D2
Vitamin D2, also known as ergocalciferol, is one of two primary forms of vitamin D, the other being vitamin D3 (cholecalciferol). Both D2 and D3 are prohormones that the body converts into calcitriol, the active form of vitamin D. Research on Vitamin D2 (Ergocalciferol) focuses on heart and circulatory health and immune function.
How much Vitamin D2 (Ergocalciferol) do people take?
The D2-vs-D3 meta-analysis pooled trials using doses from roughly 1,000 IU to 50,000 IU of ergocalciferol, given daily, weekly, or as intermittent bolus dosing. Route reported: Oral. Frequency reported: Daily, weekly, or intermittent bolus schedules across the pooled trials. These are amounts documented in the cited studies and labels for Vitamin D2 (Ergocalciferol) — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Covered by a systematic review, without regulatory approval.
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for Vitamin D2 (Ergocalciferol) in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Vitamin D2 (Ergocalciferol) entry is written from. Each number matches an inline marker above.
- [1]Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysisTripkovic L, Lambert H, Hart K, et al. · American Journal of Clinical Nutrition · 2012 · Peer-reviewed · PMID 22552031
- [2]Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysisReid IR, Bolland MJ, Grey A · Lancet · 2014 · Peer-reviewed · PMID 24119980
References & Evidence
Sources on this page that document Vitamin D2 (Ergocalciferol) dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Vitamin D2 (Ergocalciferol) studied for?
Deficiency-driven — not a performance booster
Vitamins primarily help when you're actually low. Extra doses on top of normal levels rarely add strength, endurance, or fat loss, and some fat-soluble vitamins (A, D, E, K) can build up to harmful levels.
- Confirm a deficiency with bloodwork before supplementing long-term (e.g. 25(OH)D for vitamin D, B12/folate, ferritin, magnesium RBC).
- Talk to your doctor or a registered dietitian about the right dose for your labs, medications, and conditions — especially in pregnancy, kidney/liver disease, or while on blood thinners.
- Re-test every 3–6 months and stop or lower the dose once levels are in range.
Educational information only — not medical advice. See our AI & medical policy.
What is Vitamin D2 (Ergocalciferol)?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
What does the research say about Vitamin D2 (Ergocalciferol)?
Tap a section to expand.
Source for this section: Sources for How does Vitamin D2 (Ergocalciferol) work?: Jumps to this entry in the sources and references list at the end of the page.
Source for this section: Sources for When should you take Vitamin D2 (Ergocalciferol)?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Vitamin D2 (Ergocalciferol) is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Vitamin D2 (Ergocalciferol)?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any vitamin + medication | Note | Category ruleConfidence: theoretical | Certain vitamins interact with specific medications (e.g., vitamin K with blood thinners).Source pending | Specific pairs are checked against a licensed source; confirm with your provider. |
Frequently asked questions about Vitamin D2 (Ergocalciferol)
Which studies looked at Vitamin D2 (Ergocalciferol)?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Clinical uses of 1-alpha-hydroxy-ergocalciferol(opens PubMed in a new tab)Curr Vasc Pharmacol · 2014 · PMID 23713877 · https://pubmed.ncbi.nlm.nih.gov/23713877/
- 2.Effects of Vitamin D2 (Ergocalciferol) on Parathyroid Hormone, Calcium, and Phosphorus in Humans: A Systematic Review and Meta-Analysis of Randomized Controlled Trials(opens PubMed in a new tab)Nutr Rev · 2026 · PMID 40601932 · https://pubmed.ncbi.nlm.nih.gov/40601932/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 5280793(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/5280793
Verify at
Publisher search links for Vitamin D2 (Ergocalciferol). These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- Examine.com(publisher search, opens in a new tab)Examine.com · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Vitamin D2 (Ergocalciferol)?
Plain-text summary, safe to quote verbatim:
Vitamin D2, also known as ergocalciferol, is one of two primary forms of vitamin D, the other being vitamin D3 (cholecalciferol). Both D2 and D3 are prohormones that the body converts into calcitriol, the active form of vitamin D. Research on Vitamin D2 (Ergocalciferol) focuses on heart and circulatory health and immune function.
Vitamin D2 (Ergocalciferol) cheat sheet
DoseRoutine cheat sheet · Vitamin
Vitamin D2 (Ergocalciferol)
Vitamin D2, also known as ergocalciferol, is one of two primary forms of vitamin D, the other being vitamin D3 (cholecalciferol). Both D2 and D3 are prohormones that the body converts into calcitriol, the active form of vitamin D.
Evidence
Moderate
Covered by a systematic review, without regulatory approval.
Studied range
The D2-vs-D3 meta-analysis pooled trials using doses from roughly 1,000 IU to 50,000 IU of ergocalciferol, given daily, weekly, or as intermittent bolus dosing
Route
Oral
Frequency studied
Daily, weekly, or intermittent bolus schedules across the pooled trials
Half-life
Circulating 25-hydroxyvitamin D2 has a half-life on the order of 2–3 weeks
Timing
in the morning
With food
with food
Storage
Room temperature, protected from light
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/vitamin-d2-ergocalciferol
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Vitamin D2 (Ergocalciferol) — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/vitamin-d2-ergocalciferol
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