Selenium 200µg Prolonged Release Tablets contain Selenium, which is an essential trace mineral utilized by the body’s immune system for its powerful antioxidant properties. It contributes to the protection of tissue cells against oxidative damage caused by free radicals and contributes to normal thyroid and immune function, maintenance of healthy hair and nails, and normal spermatogenesis. HealthAid Selenium is specially formulated using Sodium Selenate. This form provides an enhanced absorbable form of Selenium; allowing for maximum utilization by the body.