Vitamin A was the first vitamin that was officially named. That is why it was labeled with the first letter of the alphabet. It was identified in 1913. The first form identified is what we now know as retinol (preformed).
Retinol's function is easy to remember because its main function is on the retina (eye). The rods of the eyes within the retina rhodopsin which is a pigment which enables the rods to detect small amounts of light. The pigment cannot be made without Vitamin A. More specifically - Retinal - which is a special form.
The other form, carotenoids, are known as provitamin A. They can be found in oranges and carrots as well as the yellow vegetables and fruits. There are 600 different carotenoids. These carotenoids can be convereted into retinol.
Vitamin A is measured mainly in IU's (international units) which is the level of chemical activity belonging to the Vitamin A. Beginning in 2000, the RDA switched to expressing in terms of micrograms. This brought in the actual physical amount and allowed for a chemical activity factor.
Vit A is absorbed primarily in the small intestine. This vitamin is fat soluble (stored in the fatty tissue of the body) and is reduced with alcohol usage, cortisone medication, excessive iron intake or the use of mineral oil. Exercise can also deplete this vitamin. Because it is stored in the fatty tissue, the body can draw upon these reserves when intake is lowered. 90% of the Vit A is stored in the liver with smaller amounts in the kidneys, lungs and eyes.
Vitamin A is depleted when there are times of stress or illness. Adequate levels of zinc are required in order to release vitamin A for usage.
Recommended intake per day is approximately 5,000 iU (or 1,500 mcg RE). Deficiency signs include dry skin, changes in vision, and an increase in infections.
Sources - the two forms come from different foods. Preform A (Retinol) is derived from animal sources. It is found in the highest form in liver and fish liver oils. Egg yolks and milk products can be good sources of Vit A if obtained from non- "drugged", grass-fed animals. ProVitamin A (beta-carotene) is found in a variety of yellow and orange fruits and vegetables. It is converted to Vit A in the liver. Individuals with low thyroid, diabetes and those using large amounts of polyunsaturated fatty acids without antioxidants such as Vit E will have difficulty in converting beta-carotene to Vit A. The presence of bile salts and fatty acids in the intestine helps the assimilation of Vitamin A.
Supplement Option - Kroeger Herbs Sunny A
Why is Vitamin A Important?
Healthy Skin - both internal and external tissue integrity
Growth and Tissue Healing - involved in new cell creation including bone and promoting healthy teeth.
Antioxidation - protects cell membranes from free radicals
Lowered Cancer Risk and Supporting Immune System - optimizes function of white blood cells and integrity of mucosal lining.
Regulating Genetic Processes - the binding of retinoic acid to receptors on the nuclear membranes alters genetic processes
To find foods highest in Vitamin A check out the Worlds Healthiest Foods.
ACNE CURE - If your teen is struggling with acne, Vitamin A has been shown to assist in detoxing the liver to clear the skin. Acne is a result of an overly toxic body.
To your health...... Naturally,