While North Americans parents may stop to think about whether their children are getting enough calcium or iron or vitamin C – most don’t think twice about their iodine intake. Fortunately, they don’t really need to.
The widespread availability of iodized salt, fortified cereals and other fortified food products means that most North American children find more than enough iodine in their daily diets. Unfortunately that is not the case for just under 1/3 of the world’s children who live in parts of the world where iodine deficiency is common.
Why do we need iodine? Iodine is essential for proper functioning of the thyroid gland. The thyroid produces hormones that are essential in all stages of the lifecycle – but particularly to the physical and mental development of children. Severe iodine deficiency in utero and during early childhood is associated with dwarfism and cretinism. Moderate iodine deficiency is one of the world’s leading causes of mental impairment - associated with an average loss of 10-15 IQ points. The cumulative effect on the educational achievement and work productivity of entire communities is staggering.
Where do we get iodine? Iodine comes primarily from our food and water supplies. The oceans have a naturally high iodine content and so seafood and sea salt are very good sources of iodine. In contrast, the iodine content of land-based plants and animals varies greatly based on the quality of soil in the region where they are grown. Widespread flooding and erosion has caused much of the world’s soil to be deficient in iodine. It’s particularly bad in high mountains like the Himalayas, Andes and Alps and places with frequent flooding like Bangladesh and India.
What can be done? The most common way to improve iodine intake
at the population level is through fortification of table salt with
iodine. (According to the International Council for the Control of
Iodine Disorders, about 50% of US salt sold is iodized compared to100% of
Canadian table salt). This simple and
inexpensive method (estimated to cost 10 cents per person per year) requires
that salt be processed in central locations and that there is good
transportation infrastructure to make it available in markets and supermarkets.
Other food products like soy sauce, flour and breakfast cereal are also fortified
in certain countries. The iodine content of soil can be improved through adding
iodine to irrigation water or with fertilizer.
What can you do? Be informed and be an advocate! According to the Network for Sustained Elimination of Iodine Deficiency, 20 years of efforts have expanded coverage for iodized salt to 70% of the world’s population. Reaching the last 30% is critical. Read this recent New York Times op-ed by columnist Nicolas Kristof “Raising the World’s IQ” . Consider supporting the works of organizations such as Kiwanis International and UNICEF who promote salt iodization and address other early childhood nutrition issues.