Overview

Powerful antioxidant. Protects against oxidative stress.Selenium is one of several nutrients known to have antioxidant properties, meaning selenium plays a part in chemical reactions that stop free radicals from damaging cells and DNA. Free radicals are unstable molecules from environmental toxins, or from byproducts of the human body's metabolism. Antioxidant supplements, including selenium, are often touted to help prevent to heart disease, cancer and vision loss.Selenium supplements in particular are purported to help people with asthma, and reduce the risk of rheumatoid arthritis and cardiovascular disease. Selenium levels drop with age, so some have claimed selenium can slow the aging process, cognitive decline and dementia. Low selenium levels are also implicated in depression, male infertility, weak immune systems and thyroid problems.Selenium is said to slow the progression of HIV and counteract the poisonous effect of heavy metals. Dandruff shampoos use selenium sulfide as a topical treatment; however, this form of selenium can cause cancer if ingested. Headaches, nausea and vertigo symptoms from intracranial pressure are said to be improved by selenium supplements. Selenium is also said to improve malabsorption in the digestive tract, particularly among children.