What is Selenium? Selenium is an essential trace element that the body needs for good health and proper functioning. It is found in soil and water and is bioconcentrated by soil plants. Plants and animals that live in places where the soil is rich in selenium contain large amounts of this mineral. Selenium exists in inorganic and organic forms. Inorganic selenium occurs in soil as selenite and selenate, while organic selenium occurs as selenoproteins such as selenocysteine ​​and selenomethionine. Plants accumulate inorganic selenium in the soil and convert it to the organic form, which is consumed by animals and humans. In the body, selenium is incorporated into amino acids like methionine to form selenomethionine. It is mainly stored as protein in skeletal muscles, which accounts for up to 46% of the total selenium in the body. Other forms of organic selenium can be converted to selenophosphate for the synthesis of other selenoproteins. Selenium is essential as a cofactor for certain enzymes that help maintain normal body functions. For example, it contributes to the reduction of glutathione peroxidase enzymes, which have antioxidant activity. It also acts as a cofactor for thyroid hormone enzymes and is therefore important in all activities of the thyroid gland. Food Sources of Selenium Foods rich in selenium include seafood, organ meats, muscle meats, dairy products, grains, bread, poultry and eggs. Nuts, especially Brazil nuts and walnuts, are great selenium-containing foods. Eating just 6 to 8 pieces of Brazil nuts can provide more than 700% of the daily value (DV) of selenium recommended by the U.S. Food and Drug Administration (FDA). Many types of fish, such as cod, tuna, halibut, sardines, herring and red snapper, contain good selenium... middle of paper ...... the amount of selenium one has Need for adequate nutrition in most healthy people have been defined as: GroupRecommended Dietary Allowance (micrograms/day)Children 0 to 3 years 10 to 20 Children 4 to 8 years 20 to 30 Children 9 to 13 years 40Au above 14 years55Pregnant women60 to 65 Breastfeeding women70 to 75 Tolerable upper intake levels (UL) for selenium:UL groups (micrograms)Birth to 6 months457-12 months601-3 years904-8 years1509-13 years28014-18 years40019+ years400Pregnant400Breastfeeding400 Works citedWebMD. Selenium. http://www.webmd.com/vitamins-and-supplements/lifestyle-guide-11/supplement-guide-seleniumNIH. Selenium. http://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/Mayo Clinic. Selenium supplement (oral). http://www.mayoclinic.org/drugs-supplements/selenium-supplement-oral-route/description/drg-20063649