Selenium plays a key role in metabolism. Naturally selenium is found in the soil and appears in water and some foods. Selenium’s popularity came because of the antioxidant properties it contains which helps to protect cells from damage. Found naturally in food like brazil nuts or walnuts, tuna, herring, beef and poultry and also grains the amount in the food depends a lot by the quality of the soil. While thyroid hormone replacement is often necessary for Hasimoto’s selenium may aid in treatment. Supplementation of selenium has been shown to have a significant impact on inflammatory activity in thyroid-specific diseases. While selenium is an excellent supplement always consult your doctor to find out if selenium or any other supplement is right for you. Results vary by individual; consult a doctor before beginning any supplements.