Iodized Salt Improves Child's Iodine Status, Mental Development, and Physical Growth in a Cluster Randomized Trial in Ethiopia

The effectiveness of iodized salt programs to improve mental development and physical growth has not been studied in children < 36 months. Using a cluster randomized design, 1835 infants 5‐11 mo old were enrolled in 60 villages in Amhara, Ethiopia. Following salt iodization legislation, iodized salt was forced early into the markets of 30 villages (intervention, I) before it became available in the 30 control (C) villages. The two groups were similar at baseline. Children (85% of the baseline sample) were re‐assessed at age 20‐29 mo. Treatment effects were analyzed using linear mixed models. The median endline urinary iodine concentration (UIC) was significantly higher in group I (161.6 vs 124.0 µg/L; p<0.001). Group I had significantly higher scores at reassessment on three of the four Bayley‐III subscales: cognitive (std mean 6.40 vs 6.14; p<0.05), receptive language (std mean 7.19 vs 6.92; p<0.05), and fine motor (std mean 7.97 vs 7.59; p<0.05). Moderator analysis indicated that length‐for‐age in children was higher in group I for those with high household assets. UIC was higher in I vs C children with an unschooled mother, unimproved water, and no recent illness. These results support universal salt iodization to improve children's life. [Funded by Micronutrient Initiative, Canada]