Iodine Deficiency and Hypothyroidism From Voluntary Diet Restrictions in the US: Case Reports.

Iodine deficiency is rare in the United States today, and this is largely due to the effectiveness of iodization in the general food supply. Recent trends among specific populations of children in the United States include adopting food restrictions, such casein-free and gluten-free diets. Although the effect of these types of diets on overall nutrition status and certain micronutrients has been studied in children with autism spectrum disorder, the effect of these limitations on iodine levels in children has not been assessed. We present here 2 cases of iodine deficiency resulting from severe food restriction and associated primary hypothyroidism. In 1 case a classic presentation with a goiter was seen. These children were able to discontinue thyroid hormone treatment once iodine levels were normalized. There were no adverse events or unanticipated outcomes. The occurrence of these cases of iodine deficiency in the United States points to the need for thyroid function testing in children with severe food restrictions, especially those who have limited exposure to dairy, baked goods, and table salt.