OPTIMAL IODINE NUTRITION DURING PREGNANCY, LACTATION AND THE NEONATAL PERIOD

odine of maternal origin is required for brain development of the progeny during fetal and early postnatal life. Therefore, the iodine requirements of the mother are increased during pregnancy and lactation. This paper reevaluates the iodine requirements during pregnancy, lactation and the neonatal period and formulates original proposals for the median concentrations of urinary iodine indicating optimal iodine nutrition during these three critical periods of life. Based on an extensive and critical review of the literature on thyroid physiopathology during the perinatal period, the following proposals are made: the iodine requirements are 250-300 μg/day during pregnancy, 225-350 μg/day during lactation and 90 μg/day during the neonatal period. The median urinary iodine indicating optimal iodine nutrition during these three periods should be in the range 150-230 μg/L. These figures are higher than those recommended so far by international agencies.