Supplement evidence

150 / 575Vitamin form

Vitamin D2 (ergocalciferol)

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The short answer

Corrects vitamin D deficiency, though blood-level effects may be less sustained than D3.

Evidence and scope: Established for an indicated use
This status does not grade the ingredient for every goal, outcome, or person.
Important limitation: The benefit is tied to the stated indication, dose, and population; it is not evidence of broader disease prevention or longer life.
Before deciding: Key concern: Same vitamin D toxicity and medicine cautions; do not combine D2 and D3 unknowingly.

01 / PRACTICAL GUIDE

Dose, absorption, and combinations

These are indication-specific reference or studied ranges—not a personalized prescription. Start with the objective, then check the form, label, medicines, and health conditions.

Reference range by objective

Meeting usual needs600–800 IU/day for usual needs

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

Confirmed deficiencyPrescription or lab-directed regimens may be higher and time-limited

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

More is not automatically better. A clinician or product label may specify a different amount.

Absorption / solubilityFat-soluble / lipid-based

Fat-soluble or lipid-based. Absorption generally improves with a meal containing fat.

How it is commonly taken

Take with a fat-containing meal.

Do not combine casually

Same vitamin D toxicity and medicine cautions; do not combine D2 and D3 unknowingly.

Dose and use source ↗

Dose and use links lead to primary or official source material. Search links are discovery tools, not proof that every returned paper applies.

02 / EVIDENCE

What the research says

We keep supportive, mixed, negative, safety, and contextual findings together. The headline never replaces the underlying papers.

1research papers in this ledger

24unique primary studies represented

1,277unique participants represented

These are audited counts for this JIVANA collection, not search-result totals. Participants are counted once when multiple papers use the same cohort; review papers are not added again to participant totals.

Open the research timelineResearch timeline

Entries are ordered by publication year. A study period appears only when the source reports it.

2021

Mixed or qualifiedPMID 34684328

Vitamin D2 versus D3 for improving vitamin D status

Vitamin D3 raised total 25-hydroxyvitamin D and lowered parathyroid hormone more than D2 across varied settings, with smaller differences at lower doses. This comparative biomarker evidence does not show that D2 is ineffective for treating deficiency, nor does it establish differences in fractures or other clinical outcomes.

Published: 2021n=1,277 participants24 primary studies represented

Study design and methods

Design: Systematic review and meta-analysis of 24 randomized and nonrandomized controlled studies
Population: 1,277 apparently healthy participants
Intervention: Vitamin D2 (ergocalciferol) versus vitamin D3 (cholecalciferol) across varied doses, schedules, and vehicles
Outcome: Total 25-hydroxyvitamin D, vitamin-specific metabolites, parathyroid hormone, strength, and bone mineral density

Funding or conflict note: The authors declared no conflicts of interest.

Open research record ↗

Unscreened discovery appendix—not evidence154 candidate publicationsSearch run: Aug 21, 2026

Complete for the displayed PubMed query at the search timestamp—not for all databases or every possible synonym. Candidates can be irrelevant, duplicate the same study, or report negative findings. They are never summed as evidence or participants until screened.

03 / SOURCES

Start with the source material

Official evidence overviewPubMed bounded human-evidence search Live PubMed discovery searchNational Library of Medicine

The live search is for discovery only. Search-result counts change and are not included in the audited totals above.

Recent PubMed discovery recordsDirect links to the first 12 records returned by the reproducible search. These are discovery candidates—not reviewed summaries or a count of supportive findings.

04 / EXPERT CONTEXT

Expert context—not evidence

Expert positions are dated context—not scientific evidence. They never raise the evidence status or become consensus by repetition.

No direct, source-verified endorsement is currently recorded. Research authorship or discussion alone is not treated as endorsement.