The three foods richest in Vitamin D are salmon, mackerel and mushrooms, particularly if caught in the wild, due to exposure to direct sunlight. Some other foods rich in Vitamin D are fatty fish, dairy products, egg yolks, beef or calf liver, water-canned tuna and oil-canned sardines.
The human body receives Vitamin D best via sunlight through the skin. Because of this, there are few foods that contain it. However, it is possible to get the necessary amount with the correct diet, and some products even have Vitamin D added. For instance, in the United States most milk is fortified with Vitamin D, as are other grocery products, including orange juice and some yogurts. Cod liver oil may also be used, but it can be dangerous if too much is taken, due to its high Vitamin A content.
A few main benefits of Vitamin D are increased calcium absorption and bone health. However, too much Vitamin D can lead to high calcium levels in the heart, which may cause many other medical problems.
Vitamin D is a fat-soluble vitamin, meaning it gets stored in skin-tissue unlike water-soluble vitamins, which are not stored in the human body at all. The other fat-soluble vitamins are A, E and K.