Vitamin AWhat is Vitamin A? Vitamin A is a family of fat-soluble vitamins. Retinol is one of the most usable forms of vitamin A, and is found in animal foods such as live and eggs, as well as some fortified food products. Retinol is often called preformed vitamin A. Vitamin A plays an important role in vision, bone growth, reproduction, cell division and cell differentiation. Vitamin A helps maintain the surface linings of the eyes and the respiratory, urinary and intestinal tracts. Vitamin A also helps maintain the integrity of skin and mucous membranes that serve as a barrier to bacteria and viruses. Sources of Vitamin A Vitamin A is found in animal foods such as whole eggs, whole milk and liver. Most fat free milk in the US is fortified with vitamin A to replace the vitamins lost when the fat is removed. Fortified cereals also often include vitamin A. Vitamin A is also prevalent in dark colored fruits and vegetables. Vitamin A Deficiency Vitamin A deficiency rarely occurs in the US, but it is still a major public health issue worldwide. It is estimated that 250,000 to 500,000 children go blind each year from a deficiency of Vitamin A, primarily in developing countries. Night blindness is one of the first signs of vitamin A deficiency. Vitamin A deficiency contributes to blindness by making the cornea very dry and promoting damage to the retina and cornea. It is also important to understand the role of Vitamin A in fighting infections. The immune system needs Vitamin A to fight infections such as measles, pneumonia, dysentery and others effectively. Young children are most prone to Vitamin A deficiency. Too Much Vitamin A The risks of high storage levels of Vitamin A include birth defects, liver abnormalities and reduced bone density leading to osteoporosis. It is extremely important for sexually active ffemales who may become pregnant and who take vitamin A supplements or acne medicines which often contain high doses of vitamin A derivatives to consult their physician about risks that may be associated with vitamin A overdoses. |
