IS ENDEMIC GOITER DUE TO A LACK OF IODINE?

Abstract

A critical review. Some investigators have found that the I intake or excretion is not lower in goitrous than in nongoitrous regions. The reports that such differences exist are based upon analyses for which no suitable controls have been published. Moreover, there is one report that the differences in the I contents of different varieties of the same vegetables, grown upon the same soil at the same time, were greater than those said to obtain between the I contents of foods in goitrous and non-goitrus regions. The use of iodized salt has not abolished goiter. In some places, the incidence has increased, and in no instance has the diminution exceeded that observed in other communities without the use of iodides. Goiters can be produced in animals upon certain diets poor in I, but to prevent them requires the addition of larger amts. of I than are found in usual diets and the accumulation of larger concns. and amts. of I in the thyroid than are found in animals on usual diets. The metabolic rate of goitrous individuals is quite normal. The I content of goiters is greater than that of normal glands, and there is a positive correlation between the size of thyroid glands and their I content. Therefore, the enlargement of the thyroids cannot be due to a lack of I.