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iodine(i'o-din?, -den?) [Gr. ioeides, violet-colored + -ine] I
Iodine is part of the hormones triiodothyronine (T3) and thyroxine (T4), and prevents goiter by enabling the thyroid gland to function normally. The amount of iodine in the entire body averages 50 mg, of which 10 to 15 mg is found in the thyroid. The adult daily requirement for iodine is from 100 to 150 µg. Growing children, adolescents, pregnant women, and those under emotional strain need more than this amount of iodine.
Iodine deficiency in the diet may lead to simple goiter characterized by thyroid enlargement and hypothyroidism. In young children, this deficiency may result in retardation of physical, sexual, and mental development, a condition called cretinism.