Selenium is an essential mineral found in soil, brazil nuts, fish, and other seafood, poultry, and whole grains. The recommended daily dose is 55 micrograms (mcg) for adults and 60—70 mcg for pregnant or breastfeeding women. Selenium is thought to help preserve elasticity in body tissues, slow aging, improve oxygenation to the heart, and help prevent blood clotting. Selenium was evaluated in patients with cancer for treatment of mucositis.