Iodine (I) is essential for the formation of the hormone thyroxine in the thyroid gland in the neck. A lack will lead to a goitre and hypothyroidism. A lack in children may cause the permanent brain damage of cretinism, and as a result it is added to salt and bread to ensure that everyone has sufficient in their diet. Seafood is another excellent source of iodine.
Adults require 150 micrograms a day in their diet, but excess is not harmful. The amount of iodine is not normally measured directly in the body.
The recommended daily dietary intake is 50 µg. in infants, 100 µg. in children and 150 µg. in adults.
Iodine is used in many different medications, particularly antiseptics, as a cream, gargle, lotion, ointment, pads, paint, powder, scrub, spray and swabs. It is widely used, safe and effective, but a small number of people are excessively sensitive to Iodine.
Taking extra iodine after a nuclear attack will help to protect the body from radiation injury.
Radioactive iodine (sodium iodide, I131) is sometimes used in medicine to destroy an overactive thyroid gland.