To assess the most relevant articles on the impact of iodine supply in at-risk populations, namely infants and young children, pregnant and lactating women.

The 2022 Iodine Global Network Annual Report confirmed the dramatic decrease of severe iodine deficiency over the last 30 years, thanks to universal iodine iodization. However, mild to moderate deficiency is still present in many countries, where recent data showed a decrease of iodine intake and an impairment of iodine status. Unfortunately, there is yet no validated biomarker to classify the iodine status at the individual level. Available data show that there is no clear evidence to link mild-to-moderate iodine deficiency to adverse health outcomes in pregnant and lactating women as well as in infants and children. The description of a negative impact of maternal iodine excess on neurodevelopment of infants is of concern.

Optimization of salt iodization (e.g. careful increase in iodine concentration in salt, use by food industry in processed foods) combined with targeted, personalized supplementation under medical supervision if needed (e.g. low intake of iodine rich foods, vegan diet) seems currently preferable to blanket supplementation.