Vitamin D can be difficult to obtain from food alone because relatively few foods naturally contain significant amounts of the nutrient. Fortified plant-based drinks, breakfast cereals and certain mushrooms can help people increase their intake, particularly those who avoid animal products.
The vitamin helps the body absorb calcium and maintain healthy bones. It also supports muscle function and plays a role in immune system activity.
According to the US National Institutes of Health (NIH), fatty fish such as salmon, trout, tuna and mackerel are among the richest natural food sources of vitamin D. Egg yolks and some other animal-derived foods contain smaller amounts, while mushrooms provide vitamin D2 in varying quantities.
For people following a vegan diet, fortified foods and appropriately selected supplements can help meet daily requirements.
Fortified plant-based drinks
Soy, almond and oat drinks are among the plant-based alternatives that manufacturers fortify with vitamin D. However, the amount varies between brands, making it important to check product labels.
The NIH lists some fortified soy, almond and oat drinks as providing about 100 to 144 international units (IU) of vitamin D per cup.
Rice drinks may also contain added vitamin D, depending on the product and market. Cashew and coconut drinks should not automatically be considered good sources, as their vitamin content depends on whether they have been fortified.
Fortified breakfast cereals, some fruit juices and certain fat spreads can provide additional dietary vitamin D. Combining these foods as part of a balanced diet can help increase intake without relying on a single source.
Mushrooms provide a plant-based source
Mushrooms are among the few non-animal foods that naturally provide vitamin D. Their vitamin D content varies, and exposure to ultraviolet light can increase the amount they contain.
The NIH reports that half a cup of sliced white mushrooms exposed to ultraviolet light can provide about 366 IU of vitamin D. Ordinary mushrooms may contain considerably less.
Mushrooms generally provide vitamin D2, while many animal-derived foods contain vitamin D3. Both forms can raise vitamin D levels in the body, although research indicates that vitamin D3 may be more effective at increasing and maintaining blood levels.
Evidence does not support a blanket claim that mushroom-derived vitamin D is always better absorbed than vitamin D from animal sources.
What about eggs and fish?
Egg yolks contain vitamin D, although the amount varies. The NIH estimates that one large scrambled egg provides about 44 IU.
Fatty fish are among the most concentrated natural dietary sources. A three-ounce serving of cooked rainbow trout can provide about 645 IU, while the same serving of cooked sockeye salmon contains about 570 IU, according to the NIH.
Fish and eggs are options for people who include animal products in their diets, but they are not suitable for vegans. Those following a fully plant-based diet can instead consider fortified foods, vitamin D supplements suitable for vegans and mushrooms with increased vitamin D content.
Sunlight and daily requirements
The body produces vitamin D when skin is exposed to ultraviolet B radiation from sunlight. The amount produced varies with factors including skin pigmentation, age, geographical location, season and time spent outdoors.
Sun exposure should not be treated as a guaranteed way to meet an individual’s needs. Excessive exposure also increases the risk of skin damage.
The NIH recommends 15 micrograms, equivalent to 600 IU, per day for people aged one to 70, including pregnant and breastfeeding women. Adults aged 71 and older need 20 micrograms, or 800 IU, daily. These figures represent recommended total intake from food and supplements, rather than a target that must come from food alone.
People who struggle to obtain enough vitamin D through their diet may need supplements, depending on their circumstances. Anyone concerned about a deficiency or considering high-dose supplementation should seek advice from a qualified health professional.
Vitamin D is essential for bone health, but claims about its wider benefits need to be assessed against the available evidence. A varied diet that includes appropriate fortified foods can help people meet their nutritional needs without relying on unverified claims about individual products.
