Re-emergence of moderate iodine deficiency in developed countries

Iodine -- which is consumed mainly via dairy products, bread, and seafood -- is essential for producing the hormones made by the thyroid gland, which have a direct effect on fetal brain development. Although the potentially harmful effects of severe iodine deficiency on brain development are well-established, very few studies have examined the effect of mild or moderate iodine deficiency during pregnancy on cognitive development in the child. The results of the study connected to the commentary clearly show the importance of adequate iodine status during early pregnancy, and the risks of even mild or moderate iodine deficiency in developing infants.

"The study showed that in those women who had lower levels of Iodine, their children had lower scores in their neurocognitive testing," said Stagnaro-Green, senior associate dean for education and professor of medicine and obstetrics-gynecology at the George Washington University School of Medicine and Health Sciences. "This study goes along with other studies that have been done in the U.K., showing lower amounts of iodine in pregnant women, yet in the U.K. there is limited availability of iodine salt, there are few recommendations of women taking extra iodine during pregnancy, and many of the prenatal vitamins do not have iodine."

Stagnaro-Green, along with Pearce, associate professor of medicine at the Boston University School of Medicine, highlight the public health policies that have worked in the past to eliminate iodine deficiency, such as voluntary salt iodisation in the U.S. in the 1920s. Unfortunately, with a decreased consumption of iodised salt (sea salt, kosher salt and most processed food contain no iodine) and other iodine sources, these policies must be revisited.

"With this study, it's clear that women should be taking prenatal vitamins with iodine and asking their physicians for them," said Stagnaro-Green.