What is Vitamin A?
Vitamin A is a fat-soluble vitamin that contributes to the maintenance of normal vision and maintenance of a normal immune system. There are two different types of vitamin A: preformed vitamin A and provitamin A (for example, beta-carotene).
Vitamin A in the Diet
Preformed vitamin A is found in meat, poultry, fish and dairy products. Provitamin A (for example, beta-carotene) is found in fruits, vegetables and other plant-based foods. The most common type of provitamin A is beta-carotene. In the United States, the estimated average requirement (EAR) for adult men is 625 mcg/day and 500 mcg/d for adult women. There is no similar recommendation in Europe.
Vitamin A and Your Eyes
Vitamin A is an essential component of a protein that absorbs light in the eye called rhodopsin. It also supports the normal functioning of the cornea.