Which type of mushroom is best for vitamin D?

December 2, 2025 •

3 min read

According to health experts, vitamin D deficiency is a global health issue, and mushrooms offer a unique plant-based solution. This guide answers which type of mushroom is best for vitamin D, revealing that while wild mushrooms often contain more, you can dramatically increase the vitamin D content of store-bought varieties with a simple technique.

Quick Summary

The best mushroom for vitamin D depends heavily on UV light exposure, rather than variety alone. Certain mushrooms, like maitake and sun-exposed button mushrooms, become potent sources of vitamin D2 when irradiated. A simple home method can boost the vitamin D content significantly.

Key Points

UV exposure is key: Commercially grown mushrooms often contain minimal vitamin D, but exposure to sunlight or UV lamps converts their ergosterol into significant amounts of vitamin D2.
Button mushrooms are a great choice: Common white button mushrooms are highly effective at producing vitamin D when exposed to UV light, making them a reliable and accessible option.
Slice to maximize exposure: Slicing mushrooms before sun exposure dramatically increases the surface area, resulting in a higher yield of vitamin D.
Morel and chanterelle mushrooms have naturally high levels: Wild varieties like morels and chanterelles are naturally higher in vitamin D due to growing in sunny environments.
Cook wisely to retain nutrients: Pan-frying or grilling mushrooms helps preserve their vitamin D content better than boiling.
Sun-dried mushrooms are a pantry staple: Dried, sun-exposed mushrooms retain high vitamin D levels for many months, making them a long-lasting nutritional resource.

Mushrooms and Vitamin D: How the Fungi Work

Mushrooms are unique in the produce aisle because they are fungi, not plants. This biological difference is key to understanding their vitamin D potential. Like human skin, mushrooms contain a sterol—ergosterol—that converts to vitamin D2 (ergocalciferol) when exposed to ultraviolet (UV) light. Standard cultivated mushrooms grown in dark, controlled environments have very low levels of vitamin D. However, by exposing them to UV light, either from direct sunlight or a UV lamp, their vitamin D2 levels can be increased dramatically.

The Critical Role of UV Exposure

Whether you're looking at wild, cultivated, or dried mushrooms, the deciding factor for high vitamin D content is sufficient UV exposure. The conversion from ergosterol to vitamin D2 can be managed both commercially and at home, transforming a modest source into a nutritional powerhouse. For home fortification, simply placing sliced mushrooms in direct midday sun for as little as 15-60 minutes can generate significant amounts of vitamin D. Slicing the mushrooms increases the surface area exposed to the UV light, maximizing the conversion.

Comparing Different Mushroom Types for Vitamin D

Different mushroom species vary in their capacity to produce and store vitamin D. While sun-exposed varieties and certain wild types are superior, all edible mushrooms that contain ergosterol can benefit from UV exposure.

Here is a comparison of common mushrooms, focusing on their potential for vitamin D enrichment:


Mushroom Type	Typical Growing Condition	Vitamin D Content (IU/100g) without UV	Vitamin D Content (IU/100g) with UV Exposure	Key Characteristics for D Production
White Button	Dark, controlled indoor farms	Very low (under 40 IU)	High (400-1,100 IU+)	Highest ergosterol content, easy to find
Portobello	Dark, controlled indoor farms	Very low	High (400-752 IU+)	Mature version of button, rich flavor
Maitake	Farmed, sometimes proprietary UV	Variable (often low)	Very high (2,242 IU+)	Some producers use proprietary methods for high D content
Shiitake	Dark growing rooms	Very low (under 40 IU)	High (effective when sliced)	Gills have high ergosterol, increasing efficiency
Oyster	Dark growing rooms	Very low (under 40 IU)	High (can exceed 1,100 IU)	Can produce large amounts, especially when sliced
Wild Chanterelle	Naturally grown outdoors	High (up to 1,200 IU)	Already high from natural sun	Naturally exposed to sunlight, variable levels

How to Create Vitamin D-Rich Mushrooms at Home

For the most reliable and highest vitamin D content, enriching your own mushrooms at home is a simple and effective method. Simply purchase your mushrooms, slice them to maximize surface area, and place them outdoors in direct sunlight for 15-60 minutes. A single layer on a tray with gills facing up is ideal for maximum exposure. Even after being refrigerated for up to a week, the vitamin D content remains high.

Maximizing Vitamin D Retention When Cooking

Once your mushrooms are fortified with vitamin D, proper cooking methods can help preserve the nutrient. Studies show that heat-intensive methods like frying without oil maintain vitamin D content better than boiling, which can lead to some nutrient loss. Pan-frying or grilling your mushrooms helps them retain a high percentage of their vitamin D2.

Conclusion

While a variety's natural vitamin D levels may vary, the most significant factor determining a mushroom's vitamin D content is its exposure to UV light. For most consumers, the most practical and reliable choice is the common white button mushroom, which has high ergosterol levels and is widely available. By simply giving them a brief sunbath, you can easily create a potent, plant-based source of vitamin D at home, rivaling the nutrient density of fortified products.

For more detailed information on vitamin D metabolism and other dietary sources, consider consulting authoritative sources.

Frequently Asked Questions

All mushrooms contain ergosterol, a precursor that converts to vitamin D2 when exposed to UV light. However, without sufficient UV exposure, most commercially grown mushrooms have very low vitamin D levels.

To increase vitamin D at home, simply place sliced mushrooms gill-side up on a tray in direct midday sunlight for 15-60 minutes. Slicing increases the surface area for maximum conversion.

Studies show that the vitamin D2 produced in mushrooms is effective at raising and maintaining vitamin D levels in the blood, especially for those who are deficient.

While it is possible for commercially pulsed-UV treated mushrooms to reach very high levels, home sun exposure is unlikely to create toxic amounts. Standard dietary intake levels are easily achievable and safe.

Mushrooms naturally produce vitamin D2 (ergocalciferol), while animals produce vitamin D3 (cholecalciferol). Both are beneficial, and D2 from mushrooms is a powerful non-animal source for vegans and vegetarians.

Yes, sun-drying mushrooms is a traditional method that significantly increases and preserves their vitamin D2 content. They can be stored for months without major loss of potency.

Fresh, UV-exposed mushrooms will retain a high level of vitamin D for about a week when refrigerated. Dried, UV-exposed mushrooms maintain potency much longer, up to several months.