Foods rich in vitamin D include fish with high fat content, egg yolks, cheese and liver. Although present in some foods, vitamin D occurs primarily in fortified foods and supplements, as documented by experts at the National Institutes of Health. Among the foods containing natural sources of vitamin D, fatty fish like mackerel, salmon and tuna contain the most.
The meat derived from the fatty fishes may pack more than 400 IU of vitamin D per 3-ounce serving, which comes close to 600 IU, the daily recommended intake of vitamin D for all people below the age of 70, while 1 tablespoon of cod liver oil may exceed 1,000 IU. That meets the daily intake goal for those aged 71 and older, who need approximately 800 IU of vitamin D daily, as noted by experts at WebMD.
Following fatty fishes, egg yolks and beef liver contain the highest amounts of vitamin D in natural foods; one large egg contains 41 IU, while a 3-ounce serving of cooked beef liver packs 42 IU. Following those foods, cheese and mushrooms contain the highest vitamin D content. One ounce of Swiss cheese contains 6 IU, while the amount in mushrooms varies. In addition to these foods, many products come fortified with vitamin D, such as cereals, milk, butter and other dairy products.