nutrient
Vitamin D2 (ergocalciferol)
A vitamin D form produced by some fungi and used in some fortified foods and supplements.
Educational draft · Human scientific and editorial review pending. About review status
Vitamin D2 and D3 both enter vitamin D metabolism, while their source and product formulation remain distinct.
How it works
What the form means
Ergocalciferol is one of the forms included under vitamin D. Vitamin D2 and D3 have distinct chemical structures and sources.
Forms
D2 is one of the two main forms of vitamin D.
Vitamin D2 (ergocalciferol) is a named chemical form within its parent vitamin family.
Evidence: Established · Source checked 2026-09-05 · Sources: NIH Office of Dietary Supplements: Vitamin D: Fact Sheet for Health Professionals
Worth knowing
The fungal form. Vitamin D2, or ergocalciferol, is produced by some fungi and is used in some fortified foods and supplements. Its source is a useful label detail when comparing products.
A closer look
A blood test measures the combined supply
After absorption, D2 is converted through vitamin D metabolism and contributes to circulating 25-hydroxyvitamin D. A total 25-hydroxyvitamin D result combines the contribution from D2 and D3; it does not identify the food or supplement that supplied them.
References
Source-checked local draft.
Human editorial review pending.