Vitamin D is produced from the cholesterol in the skin when it is exposed to the Sun. The ultraviolet B (UVB) rays from the Sun provide the energy needed for the reaction to take place in the skin. This, as a result, produces Vitamin D. You can probably get all the vitamin D you need just by going outside and sunbathing a few times per week if you live in areas where there is abundant sunlight. The only really good dietary source of vitamin D is fish liver oils such as cod fish liver oil that contain up to two times the daily value in a single tablespoon. Keep in mind that dairy products and cereals are often fortified with vitamin D. Some edible species of mushrooms and egg yolks also contain small amounts of vitamin D. Some sea foods such as salmon, tuna fish and swordfish are also rich sources of vitamin D. Vegetarians get their daily dose of Vitamin D from milk yogurt, cheese, fortified cereals, tofu and even soy-based products. Vitamin D in supplements and fortified foods is available in two forms, D2 (ergocalciferol) and D3 (cholecalciferol). These two forms of vitamin D have traditionally been regarded as equivalents based on their ability to cure rickets.

Vitamin D is completely different from other forms of vitamins. Vitamin D is actually a hormone (rather steroid hormone) that is produced from cholesterol when the skin is exposed to the Sun. This is the reason why vitamin D is sometimes referred to as the sunshine vitamin. It is absolutely essential for optimal health. These days, we do not expose ourselves to sunlight for the adequate duration. So it becomes necessary for us to get more vitamin D from our diet or from supplements. Let us begin with a simple question; What is vitamin D? Vitamin D is a fat-soluble vitamin, just like vitamins A, D, E and K. This means that it dissolves in fat or oil. Vitamin D can be stored in the body for a long time. There are two main forms of vitamin D found in our diet: Vitamin D3 (cholecalciferol): This is found in foods such as fishes that are high in omega-3 content and egg yolks. Vitamin D2 (ergocalciferol): Found generally in some mushrooms. Of the above two, D3 (cholecalciferol) is almost twice as effective as the D2 form in increasing the levels of vitamin D in the blood stream. What does vitamin D do to the body?