Iodine is a nonmetallic element, which is essential in the human diet for the correct functioning of the thyroid gland.
Lack of iodine in the diet leads to the formation of a goiter and hypothyroidism.

Iodine uses in medicine

Iodine salts may sometimes be given in the early treatment of hyperthyroidism, excessive activity of the thyroid gland.
Iodine dissolved in an alcoholic solution or combined with povidone (povidone-iodine) is used as an antiseptic skin preparation before surgical operations or to clean wounds.
Iodine preparations are also used as diagnostic aids in special X rays, such as cholecystogram (of the gall bladder), intravenous pyelogram (of the kidney), and arteriogram (of an artery).
Radioactive iodine is used in the diagnosis of thyroid gland disease, as well as in investigations of liver, lung, and kidney disorders.
The preparation loses half its radioactivity within eight days. In larger doses, it may also be used in the treatment of hyperthyroidism and cancer of the thyroid gland.