Vitamins
Vitamin D2 (ergocalciferol)
Also called: ergocalciferol, vitamin D2, calciferol
A plant or fungal form of vitamin D, often in prescription doses.
- Why people take it
- Low vitamin D.
- What the evidence says
- Raises vitamin D levels, a little less effectively than D3.
- How it is usually taken
- Doses similar to D3 (for example 1,000 to 2,000 IU a day or 50,000 IU weekly for deficiency); it raises blood levels less than D3. Made by UV-exposed mushrooms.
- Be careful
- Too much causes high calcium (nausea, kidney stones). Do not take large weekly doses without a test and a doctor.
- Medicines it can interact with
- Thiazide diuretics with high doses raise calcium. Orlistat, some anti-epileptics and steroids lower vitamin D.
Other vitamins
Common questions
What is Vitamin D2?
A plant or fungal form of vitamin D, often in prescription doses.
Why do people take Vitamin D2?
Low vitamin D.
Does Vitamin D2 work?
Raises vitamin D levels, a little less effectively than D3.
How much Vitamin D2 do people take?
Doses similar to D3 (for example 1,000 to 2,000 IU a day or 50,000 IU weekly for deficiency); it raises blood levels less than D3. Made by UV-exposed mushrooms.
Is Vitamin D2 safe?
Too much causes high calcium (nausea, kidney stones). Do not take large weekly doses without a test and a doctor.
Does Vitamin D2 interact with medicines?
Thiazide diuretics with high doses raise calcium. Orlistat, some anti-epileptics and steroids lower vitamin D.
Sources and further reading
Last reviewed 31 October 2026. Written by Satya Babu.
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