Iodine is responsible for the synthesis of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Normally, the thyroid gland contains a supply of 5-10 mg of iodine. With this amount, endogenous synthesis of thyroid hormones is ensured for about 2 months. The hormones T4 and T3 regulate numerous important metabolic processes via nuclear hormone receptors, such as:
- Thermogenesis (heat balance)
- Basal metabolic rate – hyperthyroidism (hyperthyroidism) leads to an increase in basal metabolic rate and hypothyroidism (hypothyroidism) leads to a decrease in basal metabolic rate
- Body growth
- RNA and protein biosynthesis – for cell differentiation and cell division.
- Organ development
- Bone formation
- Protein, carbohydrate, and lipid metabolism – T4 and T3 stimulate gluconeogenesis (new sugar formation), glycolysis (sugar breakdown), and liponeogenesis, among other processes, and influence various enzymes, such as malate enzyme
- Differentiation processes, for example, brain development of newborns by promoting dendrite formation and myelination (sheathing of nerves by myelin sheath formation).