Selenium is a mineral found in the soil. Selenium naturally appears in water and some foods. While people only need a very small amount, selenium plays a key role in the metabolism. It is important for the proper functioning of many processes in the body by increasing the action of antioxidants such as glutathione.
Most of the selenium in the body comes from the diet. The amount of selenium in foods depends on where it was grown or bred. Crab, liver, fish, poultry and wheat are generally good sources of selenium.
Selenium is used for diseases of the heart and blood vessels, including stroke and "hardening of the arteries" (atherosclerosis ) . It is also used in the prevention of various cancers including prostate,stomach, lung and skin.
Other recommendations on the use of selenium are:osteoarthritis , rheumatoid arthritis, chronic fatigue syndrome ( CFS ) , the mood disorder and for conditions in which the immune system such as HIV and cancer chemotherapy affected.
Some research has shown that people with low levels of selenium in the body have a greater risk of developing type 2 diabetes.
Low levels of selenium appear to be linked with an increased risk of developing osteoarthritis. But it is not known whether selenium supplements can prevent osteoarthritis .