Which leaves are high in vitamin D? Unpacking the nutrition behind plant-based sources

October 14, 2025 •

4 min read

While many people seek vitamin D from plant-based foods, it is a little-known fact that very few leaves contain significant amounts, with the most reliable plant source being certain UV-exposed mushrooms. The vast majority of naturally occurring vitamin D comes from fatty fish, fish oils, and sun exposure on the skin, not from leafy greens.

Quick Summary

Investigate the actual vitamin D content of various leaves and plant sources. Understand the role of UV exposure, the differences between vitamin D2 and D3, and find the most reliable plant-based options for increasing your intake.

Key Points

Limited Plant Sources: Most plant leaves, including common ones like spinach and kale, are not a significant source of dietary vitamin D.
UV-Exposed Mushrooms: The most reliable plant-based source is mushrooms that have been intentionally treated with UV light, which converts ergosterol into vitamin D2.
Vitamin D2 vs. D3: Plants produce vitamin D2, while animal products and skin synthesis produce vitamin D3. Vegan supplements can also provide D3 from lichen.
Fortified Foods are Key: For consistent intake, rely on fortified plant-based milks, cereals, and other products, checking the nutrition facts for vitamin D content.
Alfalfa is not a solution: While it contains some vitamin D2, the amount in alfalfa leaves is too low to be a significant dietary source.
Supplements are Most Reliable: The most effective way for vegans to ensure adequate vitamin D is through supplements, including vegan D3 options derived from lichen.
Other Leaves Are Insignificant: Trace amounts of vitamin D in other leaves are not nutritionally meaningful for human dietary intake.

The Vitamin D challenge for plant-based diets

For those following a plant-based or vegan diet, obtaining sufficient vitamin D can be a challenge. The primary natural sources are animal-derived, and while our bodies can synthesize the vitamin from sun exposure, many factors like location, time of year, and skin pigmentation can limit this production. This leads many to wonder about the vitamin D content of common plant foods, particularly leafy greens. The reality, however, is that leaves are not a reliable source of this crucial nutrient.

The truth about vitamin D in leafy greens

Contrary to popular belief, most common leafy greens, such as spinach and kale, contain negligible, if any, dietary vitamin D. Their nutritional value lies in other areas, providing ample vitamins A, C, and K, and various minerals and fiber. While some studies have explored the presence of vitamin D precursors in specific, less-common plants, these findings do not translate into a practical dietary source for humans. For example, research has identified provitamin D3 in the leaves of plants from the Solanaceae family (which includes tomatoes), but the amounts are extremely small and not present in the edible fruit. Alfalfa, often touted as a natural source, contains a minimal amount of vitamin D2, making it an insignificant contributor to daily needs.

The primary plant-based source: UV-exposed mushrooms

The most reliable plant-based source of vitamin D is undoubtedly mushrooms, but with a critical caveat: they must be exposed to ultraviolet (UV) light. When exposed to UV radiation, the ergosterol in mushrooms is converted into vitamin D2 (ergocalciferol). This is similar to how our own skin converts a cholesterol precursor into vitamin D3. The vitamin D content can vary significantly based on the amount of UV exposure. Wild mushrooms, which grow under the sun, naturally have higher levels than those cultivated in the dark. Some commercial growers intentionally treat their mushrooms with UV light to boost the vitamin D content. Always check the packaging for this information.

Comparison of Vitamin D in Plant Sources vs. Other Foods


Source	Primary Type of Vitamin D	Reliability as a Source	Comments
Fatty Fish (e.g., Salmon)	Vitamin D3	High	One of the best natural dietary sources.
Sun Exposure	Vitamin D3	Variable	Depends on location, season, and duration; body produces its own.
UV-Exposed Mushrooms	Vitamin D2	Good	Only reliable plant-based source; check product labels.
Fortified Foods (Plant-based milk, cereals)	Vitamin D2 or D3	Good	Content can be significant; check nutrition facts.
Alfalfa Leaves	Vitamin D2	Very Low	Contains minimal amounts; not a meaningful dietary source.
Spinach & Kale	Negligible	Very Low	Excellent for other nutrients, but not for vitamin D.
Certain Nightshade Leaves	Vitamin D3 (precursor)	Very Low	Not for dietary consumption; only traces found in leaves.
Supplements	Vitamin D2 or D3	High	Consistent and measured dose; vegan D3 derived from lichen is available.

Understanding Vitamin D2 vs. Vitamin D3

It is important to differentiate between the two main forms of vitamin D. Vitamin D2 (ergocalciferol) is produced by fungi (like mushrooms) and plants, while vitamin D3 (cholecalciferol) is synthesized by animal skin and can also be found in supplements derived from lichen. While both forms are effective at raising serum vitamin D levels, research suggests that vitamin D3 is more efficient and maintains levels for a longer period. For those on a vegan diet, plant-based supplements from lichen provide a reliable source of the more bioavailable D3. For more information on vitamin D, consult authoritative sources such as the NIH Office of Dietary Supplements.

How to optimize your vitamin D intake

For those relying on plant-based foods, a strategic approach is necessary to ensure adequate vitamin D levels. A combination of sources is often the best method:

Prioritize UV-Exposed Mushrooms: Seek out wild-harvested mushrooms or, more reliably, commercially grown ones that are explicitly labeled as UV-treated. Incorporate them into your diet regularly. A simple way to enhance their vitamin D content at home is to place them in direct sunlight for 15-20 minutes before cooking.
Choose Fortified Foods: Many plant-based products, including soy milk, almond milk, and certain cereals and juices, are fortified with vitamin D. Checking nutrition labels is essential to confirm fortification and the amount provided per serving.
Consider Supplements: For consistent and guaranteed intake, a supplement is the most reliable option. Vegan vitamin D3 derived from lichen is widely available for those who avoid animal products.
Safe Sun Exposure: If possible, include moderate, safe sun exposure in your routine. Exposure to UVB light is necessary for our skin to produce vitamin D3, but this can be impacted by geographic location and season.

What about other leaves?

Some lists mention other leaves, such as amaranth or fenugreek, as sources of vitamin D. While they may contain trace amounts, this is often due to contamination with fungi or is present in such low concentrations that it is nutritionally insignificant. Relying on these leaves for vitamin D is not a practical or effective strategy for preventing deficiency. Their value remains in their other vitamins, minerals, and phytonutrients.

Conclusion

In summary, the notion that common green leaves are a good source of vitamin D is a misconception. While vital for other nutritional benefits, they do not contribute meaningfully to your vitamin D needs. The only reliable plant-based dietary source is mushrooms that have been exposed to UV light. For consistent intake, particularly during winter or for individuals with limited sun exposure, fortified foods and supplements are the most effective strategies to ensure adequate levels of this essential nutrient. Incorporating a variety of these sources into your diet will help maintain proper vitamin D status, crucial for bone health and immune function.

Visit the NIH Office of Dietary Supplements for more information on Vitamin D.

Frequently Asked Questions

No, common leafy greens like spinach and kale contain negligible amounts of vitamin D. They are excellent for other nutrients like vitamins A and K, but they are not a reliable source of vitamin D for your diet.

The best plant-based food source of vitamin D is mushrooms that have been treated with ultraviolet (UV) light. This process converts a natural compound in mushrooms into vitamin D2, significantly boosting their content.

Yes, fortified foods are an excellent source of vitamin D for vegans. Many plant-based milks (soy, almond), cereals, and orange juices have vitamin D added to them. Always check the nutrition label for the specific amount.

Vitamin D2 (ergocalciferol) is produced by plants and fungi. Vitamin D3 (cholecalciferol) is produced by animal skin when exposed to sunlight. Some vegan supplements also use lichen-derived D3. While both are effective, D3 is often considered more potent at raising blood levels.

Yes, you can increase the vitamin D content of mushrooms at home by placing them in direct sunlight for 15-20 minutes, gills up. This simple trick stimulates the conversion of ergosterol to vitamin D2.

Wild mushrooms typically contain higher levels of vitamin D because they grow in the open and are naturally exposed to sunlight. Most commercially grown mushrooms are cultivated in the dark and have very low levels unless they are specifically treated with UV light.

Yes, there are vegan sources of vitamin D3. This form is often derived from lichen, which is a plant-like organism. These supplements provide the same benefits as animal-derived D3 and are a great option for vegans.