25 hydroxy Vitamin D is commonly known as Vitamin D. It is a fat soluble vitamin that is found in food. 25 hydroxy Vitamin D can also be made in our body after exposure to ultraviolet (UV) rays from the sun. Vitamin D is exists in different forms. Each form of Vitamin D has a different level of activity. Calciferol is relatively most active form of Vitamin D. Vitamin D needs a chemical conversion in the liver and kidney to make the physiologically active form of vitamin D. Active vitamin D works similar to a hormone because it increases the absorption of calcium and phosphorus in the intestine. The foremost biological function of 25 hydroxy Vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D promotes the calcium absorption to form and maintain strong bones. Vitamin D also works with a number of other vitamins, minerals, and hormones to promote bone mineralization.

Sources of 25 hydroxy Vitamin D

There are two main sources of vitamin D- food sources and the sunlight. Milk is richly fortified with vitamin D, but other dairy products made from milk, such as cheese and ice creams, contain only small amounts. Some ready-to-eat cereals available in market also contain vitamin D. The other commonly available food sources of the vitamin D are cod liver oil, Salmon, Tuna fish, Sardines and Margarine etc. Sun light is perhaps the most significant source of vitamin D, because exposure to sunlight provides most humans with their vitamin D requisite. UV rays in the sunlight trigger vitamin D synthesis in skin. Sun exposure of ten to fifteen minutes at least two times a week to the body parts without sunscreen is generally adequate to provide ample vitamin D.

Deficiency of vitamin D

Vitamin D deficiency can occur in human beings due to many reasons. Deficiency of vitamin D can occur when the intake is below recommended levels or there is limited exposure to sunlight. The deficiency can also occur when kidney cannot convert vitamin D to its active hormone form or when a person cannot adequately absorb vitamin D. The vitamin D deficiency can also cause diseases such as Rickets and Osteomalacia. Rickets is a bone disease usually found in children characterized by a malfunction to properly mineralize bone tissue. In adults this deficiency can lead to Osteomalacia, which is a muscular weakness in addition to weak bones.