Vitamin A

Overview

Vitamin A is a group of fat-soluble retinoids, including retinol, retinal, retinoic acid, and retinyl esters. Vitamin A is found in animal products, fish, cod liver oil, livers, dairy products, eggs. Vitamin A also includes carotenoids, produced by plants, leafy green vegetables, fruit, and red palm oil.

Carotenoids are converted to vitamin A in the human body. Vitamin A absorption occurs primarily from the Small Intestine. As we age this process becomes less efficient potentially requiring supplementation of Vitamin A in a liquid, mycellized form for optimal absorption.

Vitamin A supplements are most effectively utilized when they are taken in divided doses with a fat-containing, low fiber meal. The human Liver can store up to 500,000 IU except in people with a Liver disease such as Hepatitis or Cirrhosis. Vitamin A is stored in the Liver as Retinyl Esters, combined with a Fatty Acid, usually as Retinyl Palmitate, however, Liver malfunction can interfere with the absorption and metabolism of Vitamin A.  ^[1] 

Persons afflicted with Diabetes Mellitus have difficulty absorbing Vitamin A thereby requiring proper supplementation. Vitamin A is not well absorbed when applied topically. Squalene increases the topical absorption of Vitamin A.

Topic Contents

 Vitamin A - Health Benefits

 Vitamin A - Immune System Health Benefits

 Vitamin A - Substances Enhanced By

 Vitamin A - Substances/Factors that Interfere with

 Vitamin A - Substances that Enhance

 Lipogenesis Biochemical Pathway

 Vitamin A - Biochemical Pathway

Electromagnetic Radiation

 Vitamin A (large dosages of 35,000 - 100,000 IU per day) may improve the general condition of persons undergoing Radiation Therapy: if Vitamin A therapy is commenced prior to Radiation Therapy. ^[2]

 Vitamin A especially the Retinyl Palmitate form of Vitamin A applied topically may inhibit the ability of UV-B to cause Sunburn.  ^[3]

Environmental Toxins

 Vitamin A may help to protect the body from the toxic effects of Air Pollution.  ^[4]

 Persons with low levels of Vitamin A have an increased mortality (death) rate from Asbestos exposure.  ^[5]

 Vitamin A may counteract some of the toxic effects of Dioxin exposure.  ^[6]

Enzymes

 Vitamin A (Retinol and Retinoic Acid forms) may inhibit Lipoxygenase.  ^[7]

 Vitamin A may inhibit Ornithine Decarboxylase.  ^[8]

Hormones

 Vitamin A may help to lower elevated Cortisol levels.  ^[9]

Immune System Chemicals

 Vitamin A may inhibit the production of excessive quantities of Tumor Necrosis Factor  ^[10]