Vitamin d is the only vitamin not obtained from the food you eat. On the other hand, vitamin d is actually obtained by sunlight on the skin. There has been much coverage of media about the dangers of getting too much sun, but it is essential that the skin is exposed to sunlight to get the recommended daily allowance of vitamin D. In fact, the amount of time that a person has to spend in the Sun to receive a dose sufficient vitamin d is extremely small and just a few minutes a day will suffice and has not received any adverse event of the amount of ultraviolet light.

The most important function of vitamin d is to help control how much calcium is absorbed from food. Most of the calcium is used to build strong teeth and bones, but it is also necessary to send messages through the nerves and to help the muscles, such as the muscles of the heart, to the contract. Vitamin is d to ensure that there is always enough calcium in the blood to perform these tasks. Other functions which require vitamin d are related to the immune system and he is believed to be also a contribution factor to reduce the risk of cancer and, in particular, of colon cancer.

The variant of vitamin d which was formed under the skin is known as vitamin D3 cholecalciferol. This vitamin d is created when ultraviolet radiation in the light of the Sun reacts with a type of cholesterol that is found under the skin naturally. D3 becomes a more active form of vitamin d in the liver and then deviates to where most needed. Some of the vitamin d remains in the liver and the kidneys to help absorb the calcium in the blood again. The rest of the vitamin d spread to the bones to help them maintain their calcium and intestines to facilitate the absorption of calcium from food.

Although the majority of vitamin d is formed through the skin to sunlight exposure, there are some foods that contain some vitamin course. This form of vitamin d is known as vitamin D2, or ergocalciferol. It is used in the same way as the other vitamins d and is the type used to create most of the supplements of vitamin D.