The iodine is indispensable element for life that is also fundamental substract for thyroid hormone synthesis which make very important influence on protein's lipid's, carbohydrate's and highly caloric substances metabolism and are a requisite of proper man development. The pregnant women are one of population group which is the most sensitive on iodine's deficiency. The results of researches indicate on insufficient iodine intake in pregnant women diet, whose take food even according to diet's recommendation given by physician. The wide iodine's prophylaxis which was provided as yet is insufficient in case of pregnant and nursing women. It is confirmed the necessity of additional iodine supplementation. A set of control tests should be done in requires cases that inform physician about changes in function and size of thyroid gland and make possible the individualization of treatment. The supplementation doses of iodine about 150 micrograms are safe and there was not observed any side effects during their taking.