THE EFFECTS OF DIFFERENT DOSES OF ORAL IODIZED OIL ON GOITER SIZE, URINARY IODINE, AND THYROID-RELATED HORMONES

The prevention of iodine deficiency is still a worldwide concern. This study, conducted in Soja in western Sudan, was carried out to evaluat e the effects of a dose of iodized oil sufficient enough to give maxim um protection against goiter and provide an acceptable iodine supply w ithout side-effects over a sufficiently long period of time. Adult goi trous subjects (n = 117) were randomly assigned to three groups, A, B, and C, and received a single oral dose of 200, 400, or 800 mg iodine, respectively. Urine and blood samples were collected at the start of the study and monitored for 1 yr. In the 3 groups, mean serum T-4 and median urinary iodine and serum TSH values were restored to reference limits, and these were maintained for about 1 yr. In each treatment gr oup, about two thirds of the subjects displayed a reduction in goiter size, and the 400- and 800-mg doses were not more efficient than the 2 00-mg dose to accomplish normalization of thyroid hormone values. A te mporary rise in TSH was noted 1 week after iodine administration in 1, 3, and 10 subjects, respectively, and 1, 0, and 3 subjects showed bio chemical signs of thyrotoxicosis during the year after treatment with the 3 different doses. The data indicate that oral administration of 2 00 mg iodine is effective and acceptable for treating iodine deficienc y in adults for 1 yr. Because of the risks of side-effects and the sho rtage of medical resources, higher doses are not recommended.