Iodine (I) - Nutrition Trace Minerals

 Iodine (I) 

Iodine is a component of the thyroid hormones, thyroxine (T4) and triiodothy-ronine (T3). It is necessary for the normal functioning of the thyroid gland, which determines the rate of metabolism.

 

Sources.The primary sources of iodine areiodized salt,seafood, andsome plant foods grown in soil bordering the sea. Iodized salt is common table salt to which iodine has been added in an amount that, if used in normal cook-ing, provides sufficient iodine.

 

Requirements.The DRI for adults is 150 mg a day. Additional amountsare needed during pregnancy and lactation.

 

Deficiency.When the thyroid gland lacks sufficient iodine, the manu-facture of thyroxine and triiodothyronine is retarded. In its attempt to take up more iodine, the gland grows, forming a lump on the neck called a goiter (Figure 8-3). Goiter appears to be more common among women than among men. A thyroid gland that doesn’t function properly causes myxedema (hypo-thyroidism) in adults. The children of mothers lacking sufficient iodine may suffer from cretinism (retarded physical and mental development).