Iodine status in pregnant and breastfeeding women: a Danish regional investigation

Iodine is required for the synthesis of thyroid hormones, which are crucial regulators of early brain development. The source of iodine in the fetus and the breastfed infant is maternal iodine, and adequate iodine intake in pregnant and breastfeeding is of major concern. Severe iodine deficiency can cause irreversible brain damage, whereas the consequences of mild to moderate iodine deficiency are less clear. Denmark was previously iodine deficient with regional differences and a mandatory iodine fortification of salt was introduced in the year 2000. The PhD thesis investigated intake of iodine supplements and urinary iodine status in Danish pregnant and breastfeeding women after introduction of iodine fortification in a region of Denmark with previously moderate iodine deficiency. Additionally, thesis addressed mechanisms of iodiden transport to the fetus across the placenta and methodological challenges in the evaluation of urinary iodine status in prengnant and breastfeeding women.