Upper limit of iodine in infant formulas
Fisher, D.A.
Journal of Nutrition 119(12 Suppl): 1865-1867; Discussion 1867-1868
1989
ISSN/ISBN: 0022-3166 PMID: 2693650 Document Number: 346833
Iodine is the rate-limiting substrate for thyroid hormone synthesis by the thyroid gland and must be available in threshold amounts to prevent goiter and hypothyroidism. Because excess iodine can inhibit thyroxine synthesis, an upper limit of iodine in infant formulas of 75 microgram/100 kcal was proposed by the Food and Drug Administration in 1985. Review of recent studies of iodine physiology in infants and iodine content of milk suggests that a safe upper limit of iodine intake by normal, term infants should not exceed 100 microgram/kg body wt daily. Given this limit and assuming the total intake of iodine to be derived from formula, the recommendation of 1985 still seems reasonable.