Iodine supplementation: is there a need?

Abstract

To review the recent data on iodine deficiency, the impact of iodine deficiency on health outcomes and the need for iodine supplementation in at-risk populations, that is, pregnant and lactating women, infants and young children. The 2019 Iodine Global Network Annual Report highlighted that only 23 countries worldwide (including Finland, Germany, and Norway in Europe) were classified as having insufficient iodine intake in 2019, down from 54 in 2003 and 113 in 1993. Even if severe iodine deficiency during pregnancy has a negative impact on cognitive outcomes later in life, the consequences of mild-to-moderate iodine deficiency on child neurodevelopment are controversial. Two 2017 and 2019 Cochrane Systematic Reviews found no evidence that iodine supplementation in women before, during or after pregnancy improved infant and child cognitive development in areas with mild-to-moderate iodine deficiency. Likewise, a 2019 Cochrane systematic review concluded that there was no evidence of a positive impact of iodine supplementation on morbidity, including cognitive impairment, and mortality in preterm infants. There is no scientific evidence to support generalized iodine supplementation in mildly to moderately deficient settings not only in pregnant and lactating women but also in infants, either preterm or term, and in young children.