Selenium In Diet
Selenium is an essential mineral that works as part of an antioxidant enzyme. The body only needs a tiny amount of selenium. The amount is measured in micrograms (mcg). The highest levels of selenium in the body are found in the liver, kidney, heart, and spleen.
What food source is the nutrient found in?
Good sources of selenium include:
- lean red meat
- whole (unrefined) grains
- organ meats
- some nuts and seeds
The level of selenium in food depends on the amount of selenium in the soil those foods were grown in. The amount of selenium in some common foods is:
- 1 cup of low-fat milk = 3.6 mcg
- 1 serving of whole-grain cereal = 12.3 mcg
- 4 ounces of seafood = 37.9 mcg
How does the nutrient affect the body?
Selenium's main role is as part of an antioxidant enzyme called glutathione peroxidase. Selenium also works with the antioxidant vitamin E. Having enough selenium can reduce a person's need for vitamin E. They work together to protect the body's cells from free radicals. Free radicals cause damage that can lead to cancer, heart disease, and other health problems. Selenium is essential for normal development of the fetus during pregnancy. It may also protect from the toxic effects of heavy metals, such as lead poisoning.
Scientists are studying a possible link between cancer and low selenium intake. People who have liver cancer seem to have lower levels of selenium than people who have healthy liver function. People who have breast cancer also have lower levels of selenium than do healthy subjects. In theory, selenium protects against both cancer and heart disease. This is because it is an antioxidant.
The adult recommended daily allowances, called RDA, for selenium are:
- men (age 19 years and older) - 55 mcg
- women (age 19 years and older) - 55 mcg
- pregnant women - 60 mcg
- breastfeeding mothers - 70mcg
Getting too much selenium is not healthy either. High levels of selenium can cause any of all of the following problems:
- hair and nail loss
- lesions of the skin and nervous system
- possibly damage to teeth
Somer, E., MA, RD.&Health Media of America. (1995). The Essential Guide To Vitamins and Minerals (2nd ed.). New York: HarperCollins Publishers, Inc.
Murray, M., ND. (1996). Encyclopedia of Nutritional Supplements. California: Prima Publishing.
Duyff, R., MS, RD, CFCS. (1996). The American Dietetic Association's Complete Food&Nutrition Guide. Minnesota: Chronimed Publishing.
Bussey, E. (April, 2000). The Food and Nutrition Board of the National Academy of Sciences' Institute of Medicine. Press Conference. Washington (Reuters Health).
Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Beta-Carotene, and other Carotenoids. (2000). National Academy Press.
Monsen, E., PhD, RD. (June, 2000). Dietary Reference Intakes for the antioxidant nutrients: Vitamin C, Vitamin E, selenium, and carotenoids. JADA: 637.
Iowa State University Extension. April, 1997. News and Reports.