The Role of Zinc in Thyroid Hormones Metabolism

Abstract

Abstract. Thyroid hormones play an important role in body homeostasis by facilitating metabolism of lipids and glucose, regulating metabolic adaptations, responding to changes in energy intake, and controlling thermogenesis. Proper metabolism and action of these hormones requires the participation of various nutrients. Among them is zinc, whose interaction with thyroid hormones is complex. It is known to regulate both the synthesis and mechanism of action of these hormones. In the present review, we aim to shed light on the regulatory effects of zinc on thyroid hormones. Scientific evidence shows that zinc plays a key role in the metabolism of thyroid hormones, specifically by regulating deiodinases enzymes activity, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) synthesis, as well as by modulating the structures of essential transcription factors involved in the synthesis of thyroid hormones. Serum concentrations of zinc also appear to influence the levels of serum T3, T4 and TSH. In addition, studies have shown that Zinc transporters (ZnTs) are present in the hypothalamus, pituitary and thyroid, but their functions remain unknown. Therefore, it is important to further investigate the roles of zinc in regulation of thyroid hormones metabolism, and their importance in the treatment of several diseases associated with thyroid gland dysfunction.

Plasma mineral (selenium, zinc or copper) concentrations in the general pregnant population, adjusted for supplement intake, in relation to thyroid function

“…This finding is intriguing but somewhat contrary to what would be expected. A 'direct' effect was suggested in a recent review that suggested that Zn had a role in thyroid-hormone metabolism by regulating deiodinase activity and the synthesis of thyroid releasing hormone and TSH (14) ; that could explain the association found in the present study between hypothyroxinaemia and relatively low plasma Zn concentrations. A recent meta-analysis showed that patients with autoimmune disorders (including thyroid disorders) predominantly show lower serum and plasma Zn concentrations than in healthy controls (32) .…”

“…Low Se status has been associated with newly diagnosed Graves' disease and Hashimoto's thyroiditis (12,13) . Zn is also involved in thyroid hormone metabolism including regulation of deiodinase activity, thyroid releasing hormone and TSH (thyrotrophin) synthesis (14) . Low plasma Zn concentration has been associated with hypothyroidism and high concentration with hyperthyroidism (13) .…”

Identification of Oncosuppressing Effects of Seven Selenoproteins in Thyroid Cancer: Implications for Distinct Roles of Selenoproteins in Tumorigenesis

“…Yet, the speci c mechanisms how DIO1 and MTs are related with each other remain unclear. Zinc plays a key role in thyroid hormone metabolism specially by regulating deiodinases enzyme activities [27] and exerts anticancer role via many cellular processes such as antioxidant reactions, transcriptional regulations, DNA and RNA repair [28] . Since MTs are able to bind both Zinc and Selenium, it is possible that defects in DIO1 and MTs expression are attributed to changes of these physiology heavy metals in the context of thyroid cancers.…”

Correlation of Dietary Zinc Intake and Serum Zinc with Thyroid Stimulating Hormone (TSH) and Free Thyroxine (FT4) Levels in Adult Hyperthyroid Patients

“…Zinc modulating transcription factors in thyroid hormone synthesis, regulating deiodinase enzyme activity, and synthesizes TRH and TSH. 9,22 TSH describes the action of thyroid hormones on thyrotropic cells and indicates the whole metabolic status of thyroid gland. A slight increase in thyroid hormones especially FT4, will decreased secretion of TSH about 10 times.…”

“…7 Zinc is a cofactor of deiodinase enzymes which convert T4 to T3 and affect Thyrotropin releasing hormone (TRH) to stimulate TSH. 8,9 Zinc deficiency can caused by low dietary zinc intake and inadequate zinc absorption in the intestinal tract. 10 Study by Prasetyo et al (2018) showed that 74,3% of Indonesian adult population tends to have low zinc intake.…”