Vitamin D2 vs D3: Which Form Raises Vitamin D Levels Better?
Both forms can raise vitamin D levels, but meta-analyses show vitamin D3 (cholecalciferol) is more effective at raising and maintaining blood 25-hydroxyvitamin D than D2 (ergocalciferol), especially with weekly or monthly dosing. D3 is the usual choice for supplements. D2 is plant- or fungus-based and is used in some prescriptions; vegan D3 from lichen is also available.
Vitamin D comes in two main forms. Both are converted by the liver into 25-hydroxyvitamin D, the form measured in blood tests. But in the matchup of vitamin D2 vs D3, one consistently performs better.
Side-by-side
| Vitamin D2 (ergocalciferol) | Vitamin D3 (cholecalciferol) | |
|---|---|---|
| Source | UV-exposed yeast and mushrooms | Made in skin from sunlight; from lanolin or lichen in supplements |
| Raises blood levels | Yes | Yes, more effectively |
| Maintains levels | Shorter-lived | Longer-lasting |
| Vegan | Yes | Only lichen-derived D3 |
| Common in | Some prescriptions, fortified plant milks | Most supplements |
What the research shows
A 2012 meta-analysis found D3 raised blood 25(OH)D more efficiently than D2, especially with large weekly or monthly doses. A 2024 meta-analysis of daily dosing also found D3 more effective, with the gap influenced by body weight.
Both forms do raise vitamin D levels, so D2 isn't useless. It's just less efficient.
Which to choose
- Most people: vitamin D3
- Vegans: lichen-based D3, or D2 if that's what's available
- Prescribed D2 by your doctor: take it as prescribed and ask about follow-up testing
Dose reminders
Most adults need 600–800 IU a day; many take 1,000–2,000 IU. Stay under 4,000 IU long term unless supervised. See how much vitamin D is too much, and take it with a meal containing fat; see the best time to take vitamin D.
The verdict
D3 is the better choice for supplements in most cases. D2 still works, particularly when prescribed, but may need higher or more frequent doses. Learn more in our vitamin D3 guide.
Frequently asked questions
Is vitamin D2 vegan?
Yes, D2 is made from yeast or mushrooms exposed to UV light. Vegan D3 made from lichen is also available.
Why do doctors prescribe 50,000 IU of D2?
High-dose D2 capsules have long been available as a prescription in some countries. They can correct deficiency, though D3 may maintain levels better.
Sources
- Tripkovic L et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. Am J Clin Nutr. 2012
- van den Heuvel EG et al. Comparison of the effect of daily vitamin D2 and vitamin D3 supplementation on serum 25-hydroxyvitamin D concentration: a systematic review and meta-analysis. Adv Nutr. 2024
- NIH Office of Dietary Supplements: Vitamin D Fact Sheet for Health Professionals
This page is for education and is not a substitute for advice from your doctor. Read our medical disclaimer.