Iodine Status in Pregnant & Breastfeeding Women: A Danish Regional Investigation

Iodine is required for the synthesis of thyroid hormones, which are crucial regulator 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 (mild iodine deficiency in East Denmark and moderate iodine deficiency in West Denmark), and also pregnant and breastfeeding women suffered from iodine deficiency. A mandatory iodine fortification of household salt and salt used for commercial production of bread was introduced in Denmark in the year 2000. The PhD thesis investigates intake of iodine supplements and urinary iodine status in Danish pregnant and breastfeeding women after the introduction of the mandatory iodine fortification of salt in a region of Denmark with previously moderate iodine deficiency. Additionally, the PhD thesis addresses mechanisms of iodide transport to the fetus across the placenta and methodological challenges in the evaluation of urinary iodine status in pregnant and breastfeeding women.