Iodine supplementation in pregnancy.

People of all ages can be affected by iodine deficiency, however, pregnant women and children are especially at a high risk. Because of changes that occur in maternal thyroid hormone economy during pregnancy and the potential unfavorable effects of iodine deficiency on the offspring, an adequate dietary iodine intake throughout the pregnancy is highly important. Therefore, the World Health Organization, United Nations Children's Fund and International Council for the Control of Iodine Deficiency Disorders have proposed that dietary intake of iodine during pregnancy should be 200-300 microg/day to compensate for the augmented T4 requirements in pregnant women. It has been shown that in countries with a longstanding and well-established universal salt iodination program where iodine sufficiency has been reached, there is a fraction of pregnant women that still have low median urinary iodine concentration, which indicates insufficient dietary iodine. Studies performed in such countries emphasize that pregnant women should use multivitamin and/ or mineral tablets specifically prepared for the needs of pregnancy and containing iodine supplements. Only the United States of America and Canada have official recommendations concerning iodine supplementation. In other countries, no such firm decisions have yet been made by medical community and public health authorities. In Croatia, an iodine sufficient country, the situation is the same. There is a need to collect adequate data on iodine supplementation and urinary iodine during pregnancy, along with the universal salt iodination program, so that definitive conclusions can be made.