Vitamin D Guide

Vitamin D is the only vitamin that can be found in processed foods. Instead, vitamin D is actually found in sunlight on the skin. There has been a lot of media coverage about the dangers of getting too much sun. Still, the skin must be exposed to the sun to get the recommended daily dose of vitamin D. In fact, the amount of time a person should spend in the sun to get enough of this ultra-violet light obtained.

FUNCTION VITAMIN D

The most important function of vitamin D is to help control the amount of calcium in the diet. Most of the calcium is used to build strong teeth and bones, but it is also needed to send nerve messages and help muscles, such as the heart muscle, to be strong. Vitamin D ensures that there is always enough calcium in the blood to perform these functions. Other functions that require vitamin D are related to the immune system and are also believed to reduce the risk of cancer and, in particular, colon cancer.

VITAMIN D & SKIN

The variation of vitamin D formed under the skin is known as vitamin D3 or cholecalciferol. This vitamin D is produced when ultraviolet light in the sun responds naturally to the type of cholesterol found under the skin. D3 is converted to the active form of vitamin d in the liver and is diverted to most needed. Some D vitamins live in the liver and kidneys to help restore calcium in the blood. The remainder of vitamin D is spread in the bones to help it retain calcium and its intestines to help absorb calcium from food.

SUNLIGHT SOURCE OF VITAMIN D  

Or most vitamin D supplements are made by exposing the skin to sunlight rather than certain foods that naturally contain vitamins. This form of vitamin D is known as vitamin D2 or ergocalciferol. This is used in the same way as other D vitamins and is used to create many vitamin D supplements.

VITAMIN D & HORMONES

Vitamin D is both a nutrient we eat and the hormone produced by our bodies. It is a fat-soluble vitamin that has long been known to help the body absorb and retain calcium and phosphorus; both are important for bone formation. Also, laboratory studies show that vitamin D can reduce the growth of cancer cells, help control infections and reduce inflammation. Many organs and tissues contain vitamin D receptors, which play important roles outside of bone health, and scientists are actively investigating other possible activities.

VITAMIN D & FOOD

Few foods are naturally rich in vitamin D, or other foods are fortified with vitamins. For most people, the best way to get enough vitamin D is to take a supplement because it is difficult to get enough food. Vitamin D supplements are available in two ways: vitamin D2 (“ergocalciferol” or pre-vitamin D) and vitamin D3 (“cholecalciferol”). Both are also naturally occurring species produced in the presence of ultraviolet-B (UVB) rays, hence its nickname, "sun vitamin," but D2 is produced in plants and fungi and D3 in animals, including humans. The production of vitamin D on the skin is a natural source of vitamin D. Still, many people do not have adequate levels because they live in areas where sunlight is limited in winter or because they have limited sunlight due to being in too much time. Also, people with dark skin tend to have lower blood levels of vitamin D because pigment (melanin) acts as a shade, reducing vitamin D production (and reducing the harmful effects of sunlight on the skin, including skin cancer).