Iodine is one of several micronutrients in the diet that influence the development of the infant brain. Hence, the effects of both maternal iodine deficiency during pregnancy and iodine deficiency during a child’s early years can be far reaching.

A scientific statement from the European Food Safety Authority claims there is a cause and effect relationship between a woman’s iodine levels during pregnancy and her child’s intelligence.

Severe maternal iodine deficiency during pregnancy has been shown to be associated with lower IQ scores in their children during the early school years, compared with those whose mothers were not iodine deficient while pregnant. But even mild iodine deficiency in pregnant women can result in adverse educational outcomes: an Australian study found affected children performed badly in spelling, grammar and English literacy. After adjusting for socioeconomic factors, reduction of spelling ability remained significant.

The good news is that supplementing a woman’s iodine intake before and during pregnancy may protect her child from adverse cognitive effects.

A meta-analysis showed that in regions where there is severe iodine deficiency, iodine supplementation may modestly improve perceptual reasoning and global cognitive index in school-aged children. Iodine supplementation for mild to moderate iodine deficiency also improved cognitive performance.