Optimal Iodine Nutrition during Pregnancy, Lactation and the Neonatal Period

Iodine 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 increasedduring pregnancy and lactation. This paper reevaluates the iodine requirements duringpregnancy, 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 #g/day during pregnancy, 225-350 #g/day during lactation and 90 #g/day during the neonatal period. The median urinary iodine indicating optimal iodine nutrition during these three periods should be in the range 150-230 #g/L. These figures are higher than those recommended so far by international agencies.