Why Vitamin A is Important For Your Body
Vitamin A Sources, Benefits, Functions, RDA, Deficiency and Toxicity
Vitamin A is an essential vitamin that plays a vital role in the growth and development of your body. Our body cannot manufacture it and therefore has to be supplied through diets.
Vitamin A is naturally available in many foods or added to some processed foods, such as milk and cereal. You can get the recommended amount from a variety of foods you eat or from dietary supplements.
In this article we will discuss about Vitamin A benefits, its functions, food sources, effects of deficiency and toxicity as well.
What is Vitamin A
Vitamin A is actually a group of fat-soluble vitamins which are known as retinol, retinal and retinyl esters.
You can get two types of vitamin A from your diet: Preformed vitamin A from animal sources and Provitamin A from plant sources.
Preformed vitamin A is found in the form of retinol and Provitamin A is found in the form of carotenoids. One such carotenoid is beta-carotene.
To use them, your body first convert both types of vitamin A to retinal and retinoic acid, which are the active forms of the vitamin.
When vitamin A intake is sufficient, 90% of total body vitamin A is stored in your liver as retinyl esters.
Preformed vitamin A is well absorbed and utilized by humans at absorption rates of 70–90%. In developed countries up to 75% of dietary vitamin A is obtained from preformed vitamin A.
Provitamin A is absorbed much less efficiently, at rates of 20–50%. In developing countries, though, 70–90% of vitamin A is obtained from provitamin A.
