Sodium Selenite (selenium) is a trace mineral that is essential for many bodily processes and is needed for optimal health. It acts as an antioxidant, helping to protect against harmful free radicals. People with gastrointestinal issues may experience decreased absorption of selenium, but supplementing with sodium selenite can help to fulfil their daily serving of selenium. Ideal selenium supplement for individuals on yeast- or sodium-restricted diets, and well tolerated by most individuals.