D2 and D3 have different common starting materials
Vitamin D supplements commonly contain ergocalciferol, D2, or cholecalciferol, D3. NIH describes commercial D2 production using ultraviolet irradiation of ergosterol from yeast. D3 is commonly made by irradiating 7-dehydrocholesterol obtained from sheep-wool lanolin. [1]
These are manufacturing sources, not a description of how much nutrient remains in an untreated piece of yeast or wool. Processing produces a defined vitamin ingredient that is then formulated into the finished supplement. [1]
Animal-free D3 also exists
NIH identifies lichen-derived D3 as an animal-free option. Therefore, neither “all D3 is vegan” nor “all D3 is animal-derived” is correct. D2 and D3 are chemical identities; a sourcing statement adds information about how the ingredient was obtained. [1]
If avoiding animal-derived materials is important, ask the manufacturer about the vitamin source and processing. Also check the rest of the product, including the capsule shell and other ingredients. An animal-free active ingredient does not establish animal-free status for an entire multicomponent product. [1]
What source can tell you about function
Both D2 and D3 can increase blood 25-hydroxyvitamin D. NIH reports that D3 generally raises and maintains this marker more effectively, while both forms are absorbed. That comparison concerns the nutrient forms and measured status marker; it does not make lanolin a therapeutic ingredient or establish that one retail brand is best for every person. [1]
The reason for supplementation, total intake and the actual product remain relevant. Source preference is a useful purchasing distinction, but it should not be mistaken for an individualized dose recommendation. [1]
A hypothetical vegan-product check
Imagine two D3 bottles with matching nutrient amounts. One identifies lanolin and the other identifies lichen. Their stated sources differ even though both contain cholecalciferol. For the lichen product, checking the remaining formulation completes the source inquiry rather than stopping at the front-label claim. [1]
| Description | What it tells you |
|---|---|
| D2 | Ergocalciferol; commonly produced from yeast ergosterol |
| D3 from lanolin | Cholecalciferol from an animal-derived starting source |
| D3 from lichen | An animal-free vitamin source; check the complete product |
Sources for this article
- Vitamin D - Health Professional Fact Sheet
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product.