Selenium is a trace mineral. It is involved in many bodily processes. Selenium exhibits both antiviral and antioxidant activity. It also increases the antioxidant activity of vitamin E. Selenium deficiency has been associated with the development of cardiomyopathy (a form of heart failure), asthma, cancer, and cataracts. Symptoms of selenium deficiency include muscle soreness, frequent colds/flu or other illnesses, and anemia. Selenium doses should be limited to 400-850 micrograms per day. Symptoms of selenium toxicity include hair loss, skin lesions, nervous system abnormalities, digestive dysfunction, and a garlic-like breath odor. Selenium is found in foods such as crab, liver, fish, poultry, and wheat.
A recent study showed that patients with higher levels of selenium had a lower risk for the development of osteoarthritis of the knees. Osteoarthritis is a condition in which the cartilage in a joint erodes. This causes bones to rub together, causing pain. It typically occurs in large joints (hip, knee). More studies are needed to evaluate whether or not selenium supplements can be used to prevent or treat arthritis.