Selenium Dietary Supplement Fact Sheet

Minerals are inorganic compounds that the body requires to carry out its normal functions. Minerals are divided into two classes: major minerals and trace minerals. Selenium is a trace mineral, which means it is needed in very small amounts by the body. Although only small amounts of selenium are required, the mineral still plays an integral role in good health.

Functions of Selenium

Selenium is an important component of various enzymes that are responsible for regulation of thyroid hormones in the body. Selenium also acts as an antioxidant, which can help prevent damage to your body from free radicals.

Recommended Daily Intake

Both adult men and women should aim to consume 55 micrograms, or mcg, daily. Most of the selenium in the American diet comes from meat, seafood, cereal, grains, dairy, fruits and vegetables. "Nutrition and You," by Joan Salge Blake, notes that the amount of selenium in the foods you eat varies based on the soil in which the food is grown.

Those Who Need Supplementation

According to the Office of Dietary Supplements, people with gastrointestinal disorders, such as Crohn's disease, are at the highest risk of selenium deficiency. People with iodine deficiency also have an increased need for selenium, although iodine deficiency in the U.S. is rare. The Office of Dietary Supplements notes that there is not enough research to support selenium supplementation for otherwise healthy individuals.

Benefits of Selenium

Death from certain cancers, including lung, colorectal and prostate, is lower among people with higher levels of selenium in their blood. The incidence of skin cancer is also higher in those with low selenium intake. Selenium acts as an antioxidant and also has the potential to slow the growth of tumors. The development of rheumatoid arthritis is also higher in those with lower levels of selenium in their blood. Selenium can help control the free radicals that cause the symptoms of arthritis, according to the Office of Dietary Supplements.

Warnings

Selenium can hinder the blood-clotting process. Because of this, you should not take selenium supplements if you are taking any anti-coagulants or blood-thinning medications. The combination can lead to excess bleeding and increased bruising. Selenium can also slow the breakdown of sedative medications. Taking selenium and sedative medications together can increase drowsiness and the possibility of side effects. In addition, long-term use of selenium supplements can cause muscle tenderness, lightheadedness, liver problems, kidney problems and tremors, according to Medline Plus.