Fundamentals of Human Nutrition/Vitamin E< Fundamentals of Human Nutrition
7.3 Vitamin EEdit
Common sources for Vitamin E include vegetable oils, like canola oil, sunflower oil, safflower oil, olive oil, corn oil, and wheat germ oil. 1 tablespoon of wheat germ oil provides 100% daily value for Vitamin E. (NIH, 2013) Sunflower seeds, almonds, peanuts, and hazelnuts are also good sources of Vitamin E. Some fruits and vegetables also contain Vitamin E, including spinach, broccoli, tomato, kiwi, and mango.
Vitamin E functions as an antioxidant in the body. Free radicals can cause damage to cells, tissues, and organs. Free radicals are unstable and without one electron, the way they work is by taking a electron from a molecule or a structure, thus leaving it without an electron, making it unstable and changing its function to that of a free radical. Vitamin E stops free radicals from making this damage to the body, by donating one of their electrons to the free radical, thus stopping it from causing any more damage. When Vitamin E gives away its’ electron, it becomes inactive. Doing this stops the oxidation of polyunsaturated fatty acids. Because of its’ role as an antioxidant, some evidence suggests that Vitamin E may protect against hypertention and cardiovascular disease. However, this is shown through a diet of Vitamin E rich foods, as opposed to Vitamin E supplements. (Tangney, 1996)
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The dietary requirements are for the alpha-tocopherol form of Vitamin E only, because alpha-tocopherol is the only form of Vitamin E that is kept in the body. The Recommended Daily Allowances (RDA) for Vitamin E in adults is 15 mg per day. The RDA for males and females are the same, unless the female is lactating, then the RDA increases to 19 mg per day. The Upper Level (UL) of Vitamin E for adults is 1000 mg per day.
Vitamin E deficiency is very rare. People with fat malabsorption diseases, like cystic fibrosis and Chron’s disease are more likely to develop a vitamin E deficiency. Malabsorption disease prevents the bowel to absorb nutrients or pertinent fluids. Lack of absorption prevents Vitamin E from doing its’ job- stabilizing free radicals as part of the antioxidant process. Vitamin E deficiency can cause erythrocyte hemolysis, which is when red blood cells break open, due to the oxidation of polyunsaturated fatty-acids in the cell’s membrane. Vitamin E deficiency can cause muscular and neurological problems, anemia, and retinopathy. Treatment is usually Vitamin E supplementation.
Vitamin E toxicity is very uncommon, and is not usually achieved from intake from foods. However, Vitamin E toxicity can occur from excessive supplements. Excessive amounts of Vitamin E can mess up Vitamin K’s clotting ability and cause blood to thin, increasing the possibility of hemorrhage. (Kaahe, 2013)
Tangney, C. (1996). Vitamin E and Cardiovascular Disease. Nutrition Today, 13-22. Retrieved August 4, 2015, from http://www.researchgate.net/publication/232156492_Vitamin_E_and_Cardiovascular_Disease
Vitamin E - Vitamin E Toxicity - Health Encyclopedia. (2013). Retrieved August 4, 2015, from https://www.kaahe.org/health/en/915-vitamin-e/915-6-vitamin-e-vitamin-e-toxicity.html
Vitamin E. (2013, June 5). Retrieved August 4, 2015, from https://ods.od.nih.gov/factsheets/VitaminE-HealthProfessional/
Whitney, E., & Rolfes, S. (2002). Understanding nutrition (9th ed.). Belmont, CA: Wadsworth.