A 30-year study on iodine and children’s intellectual ability in China

A study published by the Chinese Journal of Endemiology, assessed the intellectual development of school-aged children in Baicheng County before and after the implementation of iodine fortification strategies. At first, children were given intermittent iodine supplements from 1989-2009. This was followed by continuous and effective fortification of salt with iodine from 2010-2018.

The study observed changes in the intellectual development of schoolchildren aged 8-10 years in Baicheng County at five different time points (1989, 2002, 2006, 2012, and 2018). A total of 660 Uyghur children were surveyed using the Combined Raven’s Test for rural populations in China (CRT-RC), a validated tool for assessing IQ. The research design accounted for factors such as the Flynn effect (the rise of population IQ over time) and demographic shifts.

The study showed that the intermittent supplementation from 1989-2009 did not effectively protect children’s intellectual development, but that continuous consumption of iodized salt had obvious positive effects on children’s normal intellectual development following sustained iodine supplementation efforts.

Read the full article from the IDD Newsletter Volume 53 Issue 2.