Vitamin D is the only nutrient your body produces when exposed to sunlight.

However, up to 50% of the world’s population may not get enough sun, and 40% of U.S. residents are deficient in vitamin D.

Mushrooms
Excluding fortified foods, mushrooms are the only good plant source of vitamin D.

Like humans, mushrooms can synthesize this vitamin when exposed to UV light.

However, mushrooms produce vitamin D2, whereas animals produce vitamin D3.

Though vitamin D2 helps raise blood levels of vitamin D, it may not be as effective as vitamin D3.

Nonetheless, wild mushrooms are excellent sources of vitamin D2. In fact, some varieties pack up to 2,300 IU per 3.5-ounce (100-gram) serving nearly three times the DV.

On the other hand, commercially grown mushrooms are often grown in the dark and contain very little D2.

Certain brands are treated with ultraviolet (UV light). These mushrooms can provide 130–450 IU of vitamin D2 per 3.5 ounces (100 grams).

Mushrooms can synthesize vitamin D2 when exposed to UV light. Only wild mushrooms or mushrooms treated with UV light are good sources of vitamin D.

Egg yolks
People who don’t eat fish should know that seafood is not the only source of vitamin D. Whole eggs are another good source, as well as a wonderfully nutritious food.

While most of the protein in an egg is found in the white, the fat, vitamins, and minerals are found mostly in the yolk.

One typical egg yolk contains 37 IU of vitamin D, or 5% of the DV.

Vitamin D levels in egg yolk depend on sun exposure and the vitamin D content of chicken feed. When given the same feed, pasture-raised chickens that roam outside in the sunlight produce eggs with levels 3–4 times higher.

Additionally, eggs from chickens given vitamin-D-enriched feed may have up to 6,000 IU of vitamin D per yolk. That’s a whopping 7 times the DV.

Choosing eggs either from chickens raised outside or marketed as high in vitamin D can be a great way to meet your daily requirements.

Orange juice
Around 75% of people worldwide are lactose intolerant, and another 2–3% have a milk allergy.

For this reason, some countries fortify orange juice with vitamin D and other nutrients, such as calcium.

One cup (237 ml) of fortified orange juice with breakfast can start your day off with up to 100 IU of vitamin D, or 12% of the DV.