In July 2013, Discover had a report of the effects of iodine on human IQs. What’s very interesting is that “The role of iodine in brain development” was published in the Proceedings of the Nutrition Society (Belgium) in 2000. In addition, a study “Timing of Vulnerability of the Brain to Iodine Deficiency” was published in The New England Journal of Medicine in 1994. Apparently, the role of iodine is a lot more important than just preventing goiters, which is why it was added to salt.
Iodized salt is still the biggest contributor to iodine in our diets. The highest natural source is saltwater fish and seafood. Foods contributing half the amount of iodine in fish are: 2 eggs, 3/4 cup navy beans, or 3/4 cup black-eyed peas.