More than 60 percent of iodine in the body is found in the thyroid gland, located near the throat. Thyroid hormones control energy metabolism, body temperature, reproduction, and growth. Iodine deficiency causes the thyroid to greatly enlarge, a condition known as ‘goiter’ . The baby of an iodine-deficient mother may have retarded physical and mental development. These days, iron deficiency is a concern in the U-S only in isolated areas where food is grown in soil that isn’t rich in iodine. Dairy cattle are fed products containing iodine, which is transferred to their milk. Some bakeries use iodine as a dough stabilizer, which is in the bread. Other dietary sources of iodine include fresh saltwater fish and seafood. People used to eat iodized salt, but this appears to be no longer necessary for most Americans. Some people are sensitive to iodine and break out in a rash if they eat too much of it. Iodine also is sometimes injected during certain types of X-ray procedures. Some overweight people mistakenly may attribute their condition to an underactive thyroid, so they start taking iodine supplements. However, in large amounts, iodine can be poisonous.