Which vegetable has the most vitamin D in it? Uncovering the surprising truth

December 30, 2025 •

4 min read

Despite popular belief, most traditional vegetables contain virtually no vitamin D, as it is primarily synthesized through UV exposure or found in animal products. The surprising exception to this rule—and the answer to which vegetable has the most vitamin D in it—lies with a unique type of edible fungi: mushrooms.

Quick Summary

The highest natural, plant-based source of vitamin D comes from mushrooms, a fungus, not a true vegetable. Their vitamin D content dramatically increases when exposed to ultraviolet light, making them an excellent choice for plant-based diets.

Key Points

Mushrooms are key: Mushrooms, a fungus, are the only natural, whole-food plant-based source of vitamin D, not true vegetables.
UV exposure is critical: The vitamin D content in mushrooms is massively increased when they are exposed to ultraviolet (UV) light.
Check your label: Conventional, commercially grown mushrooms often contain minimal vitamin D, so look for packages specifically labeled as 'UV-exposed' or 'high in vitamin D'.
Fortified foods are reliable: For consistent vitamin D intake, turn to fortified plant-based foods like soy milk, tofu, and orange juice.
Sunlight is a simple boost: You can increase the vitamin D in store-bought mushrooms at home by placing them in direct sunlight for a short period.
D2 vs. D3: Mushrooms produce vitamin D2, while animals produce D3. Both can be effective at raising blood levels, although D3 is sometimes considered more potent.

Most Vegetables Contain Almost No Vitamin D

It is a common misconception that many fruits and vegetables contain meaningful amounts of vitamin D. In reality, vitamin D is a fat-soluble vitamin that is not naturally present in significant quantities in most plants. Humans primarily get vitamin D from sun exposure or certain animal products, and for those on plant-based diets, the options are more limited. Regular vegetables like broccoli, carrots, and spinach contain negligible to zero vitamin D. This is due to a fundamental biological difference: true plants do not produce ergosterol, the precursor to vitamin D found in fungi and animals.

Mushrooms: The Unique Fungal Exception

Mushrooms are not vegetables, but fungi, and they are the sole non-animal, whole-food source of vitamin D. This is because they contain ergosterol, a compound that is converted into vitamin D2 when exposed to ultraviolet (UV) light, similar to how human skin produces vitamin D3 from sunlight. However, the vitamin D content is highly dependent on how the mushrooms are grown.

Most commercially sold mushrooms, like conventional white button or cremini, are cultivated in dark indoor environments, resulting in a very low vitamin D content. The key to unlocking their vitamin D potential is exposure to UV light, which some producers do commercially. Some varieties naturally absorb more UV light and convert more ergosterol to vitamin D2 than others.

The Power of UV-Exposed Mushrooms

Specially treated UV-exposed mushrooms, sometimes labeled as 'high in vitamin D,' can provide a substantial amount of the nutrient. A single cup of UV-exposed cremini mushrooms, for example, can contain over 1000 IU of vitamin D, far exceeding the daily value. Research also shows that maitake and portobello mushrooms, when exposed to UV, can be excellent sources.

How to Expose Your Own Mushrooms to Sunlight

You can increase the vitamin D content of your own store-bought mushrooms at home. By simply placing sliced, gill-side-up mushrooms in direct sunlight for a short period (about 15-120 minutes depending on conditions), you can significantly boost their vitamin D2 levels. The vitamin D is relatively stable and remains even after cooking.

Fortified Plant-Based Alternatives

For those seeking vitamin D from plant-based sources, fortified foods are a reliable option. Many products are supplemented with vitamin D to help people, especially vegans and vegetarians, meet their daily requirements. These foods are a consistent source, unlike the variable content in mushrooms.

Popular Fortified Plant-Based Foods:

Plant Milks: Soy, almond, and oat milks are frequently fortified with vitamin D and calcium. Check the nutrition label for specifics, as fortification levels can vary by brand.
Fortified Tofu: Similar to plant milks, some tofu is fortified with vitamin D, making it a valuable source for plant-based diets. Always check the packaging.
Fortified Orange Juice: A less-common but available option, certain orange juice brands add vitamin D. Be mindful of the high sugar content.
Fortified Cereals: Many breakfast cereals are fortified with a range of vitamins and minerals, including vitamin D.

Comparison of Vitamin D in Plant-Based Foods

To illustrate the difference in vitamin D content, the following table compares various plant-based sources. IU stands for International Units.


Food Source	Serving Size	Vitamin D Content (IU)	Notes
UV-Exposed Cremini Mushrooms	1 cup	~1100 IU	Fungi, treated with UV light
Wild Morel Mushrooms	1 cup	~136 IU	Fungi, naturally sun-exposed
Fortified Soy Milk	1 cup	100-144 IU	Fortified product
Fortified Tofu	100 g	~101 IU	Fortified product
Fortified Orange Juice	1 cup	~100 IU	Fortified product
Conventional Mushrooms	1 cup	< 40 IU	Fungi, grown in darkness
Broccoli, Spinach, Carrots	Any serving	0 IU	True vegetables, no natural vitamin D

Combining Sources for Optimal Intake

Since sunlight exposure can be limited and dietary sources can be inconsistent, combining several strategies is often the most effective approach for maintaining adequate vitamin D levels, especially for those who consume limited or no animal products. You can incorporate UV-exposed mushrooms into meals like stir-fries or soups, pair fortified plant milk with your cereal, and, if necessary, consider a high-quality vegan vitamin D supplement derived from lichen. Always consult a healthcare professional to determine your specific needs.

Conclusion

While the search for a traditional vegetable with high vitamin D is largely fruitless, the fungal kingdom provides a powerful answer. UV-exposed mushrooms offer a potent, natural, plant-based source of this crucial nutrient, far surpassing standard vegetables. By understanding how to select and prepare mushrooms, and by leveraging fortified foods, those on plant-based diets can effectively meet their vitamin D needs without relying on animal products. The best approach is often a combination of these dietary strategies and, where appropriate, sensible sun exposure. You can get more information on vitamin D from the National Institutes of Health.

Frequently Asked Questions

No, true vegetables do not naturally contain significant amounts of vitamin D. This fat-soluble vitamin is primarily found in animal products and fungi, or produced by the skin through sun exposure.

Mushrooms contain ergosterol, a substance that is converted into vitamin D2 when the fungi are exposed to ultraviolet (UV) light. The amount of vitamin D they contain depends on their level of UV exposure.

No, this is a safe and natural process. Much like human skin producing vitamin D from sunlight, mushrooms convert ergosterol into vitamin D when exposed to UV light. It is a common and approved practice for increasing their nutritional value.

Fortified orange juice can contribute to your vitamin D intake, but it is not a sole source. It is best to consume it as part of a varied diet that includes other fortified foods, UV-exposed mushrooms, or supplements, particularly for those on a plant-based diet.

Not necessarily. While some wild mushrooms that grow in sunlight can have high vitamin D content, their levels can vary. Many store-bought mushrooms are grown in the dark and have very little, unless they are specifically labeled as UV-exposed.

While some studies suggest vitamin D3 may be more effective at raising blood levels, vitamin D2 from mushrooms is bioavailable and effective for increasing and maintaining vitamin D status, particularly for those with a deficiency.

Vegans and vegetarians should prioritize UV-exposed mushrooms, fortified foods (like plant milks, tofu, and cereals), and safe sun exposure. For consistent and sufficient intake, a daily supplement is often recommended, especially during winter months.