ABSTRACT
Iodine was the second element, iron being first, to be recognized as essential for health. Iodine deficiency is a common worldwide cause of endemic goiter and cretinism in children. Iodine deficiency is most destructive on the brain. The deficiency results in the impairment of brain development during fetal life and early infancy at the time of maximum growth rate of the brain. Various laboratory procedures are available to assess iodine deficiency, but many are not used nor necessary for establishing an iodine deficiency in a population. Expressing urinary iodine concentrations in terms of urinary creatinine concentration has been questioned when applied to areas where large inter- and intraindividual variations in urinary creatinine excretion exist. Excessive intakes of iodine are highly unlikely in the United States, but has been observed in some Japanese inhabitants living in coastal areas and have a high intake of seaweed.
