Vitamin E is a fat-soluble antioxidant. It was discovered in 1922 by Evans and Bishop. They found that it helped with reproduction in rats. The structure of Vitamin E consists of four tocopherols (alpha, beta, gamma, and delta tocopherol) and four tocotrienols (alpha, beta, gamma, and delta tocotienol). The most abundant is the alpha tocopherol and it has been found that alpha tocopherol can undo symptoms of Vitamin E deficiency in humans. In the 50s Vitamin E was rediscovered and found to be a cellular antioxidant. Because of this discovery, Vitamin E has been studies primarily as an antioxidant and many people have looked at its capability to prevent chronic disease. Epidemiology studies have found a correlation between high Vitamin E intakes and a reduced risk of cardiovascular diseases.
Brigelius-Flohe, Regina; Traber, MG (1999). Vitamin E: Functions and Metabolism. The FASEB Journal, 13 (10), pp. 1145-1155. http://www.fasebj.org/cgi/content/short/13/10/1145.
Vitamin E stops the production of ROS (reactive oxygen species) formed when fat undergoes oxidation. Scientists are investigating whether, by limiting free-radical production and possibly through other mechanisms, vitamin E might help prevent or delay the chronic diseases associated with free radicals. Serum concentrations of vitamin E (alpha-tocopherol) depend on the liver, which takes up the nutrient after the various forms are absorbed from the small intestine. Vitamin E is also involved in immune function and, as shown primarily by in vitro studies of cells, cell signaling, regulation of gene expression, and other metabolic processes
The Recommended Dietary Allowance (RDA) The RDA for vitamin E was previously 8 mg/day for women and 10 mg/day for men. The RDA was revised by the Food and Nutrition Board of the Institute of Medicine in 2000 (4). This new recommendation was based largely on the results of studies done in the 1950s in men fed vitamin E deficient diets. In a test-tube analysis, hydrogen peroxide was added to blood samples and the breakdown of red blood cells, known as hemolysis, was used to indicate vitamin E deficiency. Because hemolysis has also been reported in children with severe vitamin E deficiency, this analysis was considered to be a clinically relevant test of vitamin E status. Importantly, this means that the latest RDA for vitamin E continues to be based on the prevention of deficiency symptoms rather than on health promotion and prevention of chronic disease. The Recommended Dietary Allowance (RDA) for RRR-alpha-tocopherol (d-alpha-tocopherol) Life Stage Age Males; mg/day (IU/day) Females; mg/day (IU/day) Infants (AI) 0-6 months 4 mg (6 IU) 4 mg (6 IU) Infants (AI) 7-12 months 5 mg (7.5 IU) 5 mg (7.5 IU) Children 1-3 years 6 mg (9 IU) 6 mg (9 IU) Children 4-8 years 7 mg (10.5 IU) 7 mg (10.5 IU) Children 9-13 years 11 mg (16.5 IU) 11 mg (16.5 IU) Adolescents 14-18 years 15 mg (22.5 IU) 15 mg (22.5 IU) Adults 19 years and older 15 mg (22.5 IU) 15 mg (22.5 IU) Pregnancy all ages - 15 mg (22.5 IU) Breast-feeding all ages - 19 mg (28.5 IU)