In Denmark, household salt and bread salt were chosen as the
vehicles for iodine fortification because these foods are consumed
by (nearly) everyone. Iodine fortification was introduced on a
voluntary basis in 1998, but became mandatory in 2000. Since
then, household salt and bread salt have been fortified with
iodine at a level of 13 mg/g (80e150% of this level is permitted).
However, it is legal to sell bread and salt without iodine in
Denmark if produced in another country. The Danish investigation
of Iodine Intake and Thyroid Diseases (DanThyr) monitored
the iodine intake and the prevalence of increased thyroid volume
and other iodine-related thyroid abnormalities in two cities in
Denmark, Copenhagen and Aalborg, with slightly different iodine
intakes. Iodine excretion has been assessed in two cross-sectional
studies, one before and one after the introduction of iodine
fortification in Denmark.4,5 Moreover, results on thyroid volume
have been published.6,7