• Selenium. Selenium, a mineral needed for thyroid hormone production, helps protect the thyroid from damage caused by oxidative stress. The thyroid contains high amounts of selenium, and a deficiency can lead to thyroid dysfunction (2Trusted Source).
• Iodine. Iodine is critical for thyroid function. In fact, currently, the only known role of iodine is to support thyroid hormone production. Triiodothyronine (T3) and thyroxine (T4) are thyroid hormones that contain iodine. Iodine deficiency causes thyroid disease (3Trusted Source, 4Trusted Source).
• Zinc. The mineral zinc is required for thyroid hormone production. An optimal concentration of zinc is needed for healthy levels of T3, T4, and thyroid-stimulating hormone (TSH) (5Trusted Source).
• Iron. The thyroid needs iron to convert T4 into T3, the active form of thyroid hormone. Iron deficiency is associated with thyroid dysfunction (6Trusted Source).

Other nutrients, including B vitamins and vitamins A and E, are also needed for optimal thyroid function. Being deficient in one or more nutrients can negatively affect thyroid health and increase your risk of thyroid disease (7Trusted Source, 8Trusted Source, 9Trusted Source, 10Trusted Source).