Effects of essential metals (iron, zinc, and copper) on thyroid diseases - a narrative review

The thyroid gland is the largest endocrine organ in the human body, and alterations in its homeostasis may lead to the development of thyroid diseases. The role of essential metals such as iron (Fe), zinc (Zn), and copper (Cu) in the pathogenesis of thyroid diseases has been widely discussed, but the research results are inconsistent. In addition, the therapeutic role of these essential metal elements in patients with thyroid diseases has been significantly underestimated in the clinical practice. A disturbance in the balance of these essential metals will affect thyroid homeostasis in a variety of ways. This article synthesizes current evidence on the effects of essential metal elements (Fe, Zn, and Cu) on a variety of thyroid diseases, such as hypothyroidism, autoimmune thyroid diseases (AITD), and thyroid cancer. It will provide essential metal element-related clues for the development of therapeutic strategies and pathophysiologic studies of thyroid diseases.