Mushroom Vitamin D: D2 vs D3, Which Is Better and How to Get Enough
Quick answer: Mushrooms make vitamin D2 when exposed to sunlight or UV light, just as your skin makes vitamin D3. Both forms are absorbed, but vitamin D3 raises and keeps up blood vitamin D levels more effectively than D2, which is why most supplements use D3. UV-exposed mushrooms are a useful food source of vitamin D for vegetarians, but for people who are low, a daily D3 supplement is the more reliable choice.
Reviewed by the themycotech team · Last reviewed: October 2026 · For general information, not medical advice.
Vitamin D2 vs D3 at a glance
| Vitamin D2 (ergocalciferol) | Vitamin D3 (cholecalciferol) | |
|---|---|---|
| Made by | Mushrooms and yeast exposed to UV light | Human skin in sunlight; animals; lichen |
| Food sources | UV-exposed or sun-dried mushrooms, some fortified foods | Egg yolk, oily fish, fortified milk and oil |
| Raises blood vitamin D | Yes | Yes, more effectively and for longer |
| Vegetarian? | Yes (vegan) | Depends on source: lanolin (from sheep's wool) or lichen |
| Used in most supplements | Less often | Yes |
How do mushrooms make vitamin D?
Mushroom cells contain ergosterol. When UV light hits it, ergosterol turns into vitamin D2, the same way 7-dehydrocholesterol in our skin turns into D3. Mushrooms grown in the dark contain very little vitamin D. Placing fresh, sliced mushrooms gill-side up in midday sun for 15–60 minutes can raise their D2 content many times over, and commercial growers use UV lamps to do the same (Keegan et al., 2013).
Is mushroom vitamin D absorbed?
Yes. In a trial, eating UV-exposed button mushrooms raised blood vitamin D levels about as much as a D2 supplement of the same dose (Urbain et al., 2011). So mushroom vitamin D is real, not just a lab number. The catch is the amount: it varies widely by type, light exposure and storage, and some is lost in cooking.
Why most supplements use D3
A meta-analysis of trials found that vitamin D3 raised blood 25(OH)D levels more than the same dose of D2, especially with weekly or monthly dosing (Tripkovic et al., 2012). D3 also seems to keep levels up for longer. For someone who is low in vitamin D, a fixed daily dose of D3 is the more dependable way to get back to a healthy level.
Vitamin D in India
Even with plenty of sunshine, studies across India have found low vitamin D in a large share of adults and children, because of indoor work, covered clothing, darker skin (which needs more sun to make vitamin D), pollution and a mostly vegetarian diet. Signs can include tiredness, bone and muscle aches and frequent infections, but many people have no symptoms; a blood test (25-hydroxy vitamin D) is the only way to know.
| Source | Reliability |
|---|---|
| Midday sun on arms and legs | Good but variable: season, skin tone, time outdoors |
| UV-exposed or sun-dried mushrooms | Moderate; content varies |
| Fortified milk and edible oil | Low to moderate |
| Vitamin D3 supplement | High and consistent |
ICMR-NIN (2020) recommends 600 IU (15 µg) of vitamin D a day for adults if sun exposure is low. Higher doses are sometimes used to correct a deficiency; the commonly used safe upper limit for adults is 4,000 IU a day unless your doctor advises otherwise.
Best way to get both: food plus a D3 supplement
- Put mushrooms in the sun for 30 minutes before cooking.
- Take a vitamin D3 supplement with your largest meal; vitamin D is fat-soluble and is absorbed better with food.
- Pair it with calcium-rich foods and, for energy and nerves, vitamin B12 (see Can you take B12 and D3 together?).
- Recheck your blood level after 3 months if you were low.
Shiitake and vitamin D3 in Level Up B12 + D3
Level Up B12 + D3 gives 2000 IU of vitamin D3 and 2.5 µg of active vitamin B12 (methylcobalamin) with shiitake mushroom extract, calcium, magnesium and zinc, in 1 capsule after breakfast. See the full label on the product page, or read our shiitake guide.
Frequently asked questions
Do mushrooms have vitamin D?
Only if they have been exposed to sunlight or UV light. They then make vitamin D2. Mushrooms grown in the dark contain very little.
Is vitamin D2 or D3 better?
Both work, but vitamin D3 raises blood vitamin D levels more effectively and keeps them up longer, so most doctors and supplements use D3.
Is vitamin D3 vegetarian?
It depends on the source. Most D3 is made from lanolin, a fat in sheep's wool, which many vegetarians accept; vegan D3 is made from lichen. Check the label if this matters to you.
How can I increase vitamin D in mushrooms?
Slice fresh mushrooms and leave them gill-side up in direct midday sun for 15–60 minutes before cooking.
Can I get enough vitamin D from mushrooms alone?
Possibly, if you eat UV-exposed mushrooms regularly, but the amount varies. If a blood test shows you are low, a D3 supplement is more reliable.
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. American Journal of Clinical Nutrition, 2012. PubMed
- Urbain P, et al. Bioavailability of vitamin D2 from UV-B-irradiated button mushrooms in healthy adults deficient in serum 25-hydroxyvitamin D. European Journal of Clinical Nutrition, 2011. PubMed
- Keegan RJ, et al. Photobiology of vitamin D in mushrooms and its bioavailability in humans. Dermato-Endocrinology, 2013. PubMed
- National Institutes of Health, Office of Dietary Supplements. Vitamin D fact sheet.
- ICMR–National Institute of Nutrition. Nutrient Requirements for Indians, 2020.
This article is for general information. themycotech products are food supplements and are not intended to diagnose, treat, cure or prevent any disease. Consult a healthcare professional if you are pregnant, nursing, on medication or managing a medical condition.
