Adequacy of iodine nutrition in the United States.

Concerns have been raised about the adequacy of iodine nutrition in the United States despite recent NHANES III data indicating that iodine intake remains generally adequate. Such concerns probably reflect misunderstanding of definitions of iodine deficiency. We review current criteria for iodine deficiency, the reasons for variability of urine iodine determinations, and their relation to interpretations of NHANES data. Although NHANES data indicate that iodine nutrition in the United States is adequate, the possibility remains that those who adhere to restricted diets may have reduced intake of iodine. Because of such possibilities, patients' diets and use of dietary supplements should be explicitly considered as a part of routine medical care.