Almost no common fruits or vegetables contain meaningful amounts of vitamin D. The nutrient is primarily produced in animal skin and human skin through sun exposure, which is why it’s so rare in the plant kingdom. But a few notable exceptions exist: mushrooms, lichens, certain microalgae, and a handful of lesser-known plants all produce detectable vitamin D, and some can deliver a significant portion of your daily needs.
For context, adults up to age 70 need about 15 mcg (600 IU) of vitamin D per day, rising to 20 mcg (800 IU) after 70.
Mushrooms: The Best Plant-Based Source
Mushrooms are the standout. They produce vitamin D2 (ergocalciferol) when exposed to ultraviolet light, using the same basic mechanism your skin uses to make vitamin D from sunlight. The catch is that most commercially grown mushrooms are raised in the dark, so they contain very little vitamin D unless they’ve been treated with UV light during or after growing.
UV-treated portobello mushrooms contain an average of about 11 mcg (446 IU) per 100 grams, though the range varies widely by producer. USDA testing found some lots as high as 25.6 mcg (1,022 IU) per 100 grams and others as low as 3.1 mcg (124 IU). That means a single serving of the better-treated mushrooms can exceed your entire daily requirement, while a lower-quality batch might cover only about 20% of it. Look for packaging that says “UV-treated” or “high in vitamin D” to get the benefit.
You can also boost vitamin D levels at home by placing store-bought mushrooms gill-side up in direct sunlight for 15 to 30 minutes before eating them. White button, cremini, shiitake, and maitake mushrooms all respond to UV light this way.
Cooking Doesn’t Destroy It
One practical concern people have is whether cooking wipes out the vitamin D. It doesn’t. Research on UV-irradiated button mushrooms found at least 95% retention of vitamin D2 after frying, baking at 200°C, and boiling. Frying and baking actually preserved slightly more than boiling, but even 20 minutes of boiling kept retention above 95%. So cook your mushrooms however you like without worrying about losing this nutrient.
Lichens: A Surprising Source of D3
Here’s something most people don’t expect: lichens produce vitamin D3 (cholecalciferol), the same form made by human skin and typically found only in animal sources. This makes lichen the only widely available plant-based source of D3, which is why it’s become the go-to ingredient in vegan vitamin D3 supplements.
Reindeer lichen (Cladonia rangiferina), which grows in northern latitudes across Russia, Scandinavia, and Canada, contains between 67 and 204 mcg of vitamin D3 per 100 grams of dry matter. That’s a remarkably high concentration. The lichen converts precursor sterols in its cell membranes into vitamin D when hit by UV radiation, and it can even do this at low temperatures below 16°C. Researchers have confirmed that even at 70°N latitude, summer UV levels are sufficient for this process.
You won’t find lichen at the grocery store, but lichen-derived D3 supplements are widely sold and are the primary way vegans access this more potent form of the vitamin.
Vitamin D2 vs. D3: Does the Form Matter?
Most plant sources provide vitamin D2, while animal sources and lichen provide D3. This distinction matters. Vitamin D3 is more effective than D2 at raising your blood levels of the active form your body uses. D3 appears to be better converted in the body at normal dietary doses, meaning you’d need more D2 to achieve the same effect. If you’re relying entirely on plant-based sources for vitamin D, this efficiency gap is worth keeping in mind.
Microalgae and Other Plant Sources
Certain microalgae also produce vitamin D3, which has drawn interest from supplement manufacturers. The marine species Nannochloropsis oceanica produces up to 1 mcg of D3 per gram of dry matter when exposed to UVB light. That’s notable because most algae don’t produce D3 at all. Testing on three other species (Chlorella minutissima, Arthrospira maxima, and Rhodomonas salina) found zero D3 production, and UVB exposure actually inhibited their growth. So this trait is species-specific, not a general feature of algae.
A few land plants contain small amounts of vitamin D or its active metabolites, though none are practical dietary sources. Alfalfa has been measured at up to 95 mcg of vitamin D per kilogram, which sounds significant until you realize that’s per kilogram of the plant. You’d need to eat enormous quantities. Waxy-leaf nightshade (Solanum glaucophyllum) contains vitamin D3 and its metabolites, but the plant is actually known for causing calcium toxicity in grazing livestock. Tomatoes and bell peppers from the same plant family have also shown trace amounts of vitamin D3 in lab analysis, but at levels too small to contribute to your diet.
Fortified Plant Foods
For most people eating plant-based diets, fortified foods are the most reliable daily source. Plant milks made from soy, almond, oat, and other bases can contain up to 205 IU of vitamin D per 8-ounce glass, following the FDA’s recently increased fortification limits. That covers roughly a third of the daily requirement for most adults in a single serving.
There’s an important caveat, though. Fortification isn’t mandatory. The USDA doesn’t require any milk, dairy or otherwise, to contain added vitamin D. While most cow’s milk in the U.S. is voluntarily fortified, some plant milks contain no vitamin D at all. Always check the nutrition label rather than assuming your oat milk is contributing to your intake. Fortified orange juice, cereals, and tofu are other options, but again, you need to verify per brand.
Putting It All Together
If you’re trying to get vitamin D from plant sources alone, UV-treated mushrooms are your best whole-food option, potentially delivering a full day’s worth in a single serving. Lichen-derived D3 supplements offer the most bioavailable plant-based form. Fortified plant milks and foods help fill the gap on a daily basis but vary by brand. And sunlight on your own skin remains the most efficient source of all, regardless of diet, since your body produces D3 directly when UVB rays hit exposed skin.