In severely iodine-deficient areas in Ecuador, Peru, Zaire and Argentina demonstrated that intramuscular injection of iodized oil decreases goiter size, normalizes parameters of thyroid function, and prevents iodine deficiency and cretinism for a period of three and five years.

In addition to cretinism, several studies have shown an association between endemic goiter and carcinoma of the thyroid, yet the results of other related studies are conflicting.