Vitamin A is a clear yellow liquid and one of the four fat-soluble vitamins, along with vitamins D, E and K. That means that it dissolves in organic solvents, and is absorbed and transported in the body in a manner similar to fats.
Vitamin A is an antioxidant that works with other vitamins and nutrients to protect your cells against damaging free radicals as well as many other vital roles in the body. It was first found in 1913, when scientists discovered it could prevent night blindness.
Because it is fat-soluble, A is potentially more dangerous than most other vitamins and can build up to toxic levels causing liver damage. For this reason, vitamin A supplements should be used with caution.
Beta-carotene supplements taken at nutritional doses are generally considered to be a safer way to get the vitamin A you need. Beta-carotene is transformed into A as your body needs it, and presents much less risk of toxicity.
Naturally occurring colorful compounds that are abundant as pigments in plants. Carotenoids include alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, and cryptoxanthin.
Benefits – A Quick List
- Reduces risk of various epithelial-cell cancers
- Essential for the growth of bones, teeth and soft tissues
- Neutralizes free radicals
- Helps maintains a stable nervous system
- Enhances immunity
People whose diets are limited in A rich foods, such as dairy foods, liver and vegetables rich in beta carotene (which the body can convert into vitamin A) can develop shortages in this essential vitamin.
Deficiency symptoms can show up as dry skin and increased risk of infections. Severe deficiencies causing blindness are not common in Western societies.
Sometimes different conditions can cause a malabsortion problem which can result in deficiencies of important vitamins. If you have a problem absorbing fats in your digestive tract, you have a higher risk of developing a vitamin A deficiency.
A high level of A deficiency has been reported in people with HIV infection. People with hypothyroidism have an impaired ability to convert beta-carotene to vitamin A.
Many studies report that adequate intake of A is associated with reduced risk of various epithelial-cell cancers (mouth, skin, lungs, bladder, breast, stomach, cervix, etc.)
Because it helps maintain healthy epithelial cells, vitamin A also helps the body create effective barriers to infection, thereby boosting overall immunity. A is also essential for the growth of bones, teeth and soft tissues.
The Micronutrient Information Center can provide more specific information about vitamin A.
A occurs naturally only in foods of animal origen, such as liver, which is the storage place for vitamin A in animals and humans; some seafood, butter, whole milk and egg yolks.
Carrots and other orange and yellow vegetables,fruits and dark green leafy vegetables contain carotenoids, which the body converts to vitamin A. The best known carotenoid is beta-carotene, which is abundant in many foods.