Iodine supplementation and intelligence testing in children:
Iodine supplementation in children with mild iodine deficiency may improve cognition. Researchers evaluate the effects of iodine supplementation in 184 children (age 10-13) with mild iodine deficiencies. The children were randomly assigned to receive either daily iodine supplements (150 mcg) or placebo daily for 28 weeks. By the end of the study, the children in the iodine group had significantly improved their cognitive scores on 2 out of the 4 tests (from the Wechsler Intelligence Scale for Children) improving picture concepts and matrix reasoning but no gains on letter-number sequencing or or symbol search were made. (30)