Selenium is a trace mineral that your body uses in small amounts. It combines with proteins to make antioxidants that help protect the cells in your body from free radical damage. Selenium is also essential for normal thyroid function.
Some research indicates there may be a lower risk of cancer and heart disease among people who have larger amounts of selenium in their diets, but there isn't much evidence for health benefits from taking selenium supplements.Daily Requirements
1 to 3 years: 20 micrograms per day
4 to 8 years: 30 micrograms per day
9 to 13 years: 40 micrograms per day
14+ years: 55 micrograms per day
Selenium is found in many plant-based foods, such as whole grains and nuts, as well as most animal-based foods.
Deficiency is rare in developed countries; however, it may contribute to heart disease, thyroid dysfunction and a weakened immune system.
Other Trace Minerals
Source:
Dietary Supplement Fact Sheet: Selenium. Office of Dietary Supplements - National Institutes of Health. Accessed February 17,2010. http://ods.od.nih.gov/factsheets/selenium/.

