Iodized salt benefits infant mental development: preliminary results from a cluster randomized trial in Ethiopia (389.4)

Iodine deficiency is thought to contribute to delayed mental development. The effectiveness of iodized salt programs to eliminate this delay has not been studied in children under 36 months. Using a cluster randomized design, 1880 infants 6 to 10 mo old were administered Bayley Scales of Infant and Toddler Development (BSID‐III) in 60 villages in Amhara, Ethiopia. Following salt iodization legislation, iodized salt was forced early into the markets of 30 villages (intervention group) before it became available in the 30 control villages. The two groups had similar socioeconomic, nutrition, and mental development scores at baseline. The same children (86% of the baseline sample) were re‐assessed with the BSID‐III when 20 to 29 mo of age. Analysis was done with a linear mixed model. The intervention group had significantly higher scores at reassessment on three of the four subscales: cognitive (std mean 6.4 vs 6.1, p<0.05), receptive language (std mean 7.2 vs 6.9, p<0.05), expressive language (std mean 6.4 vs 6.2, ns), and fine motor (std mean 7.94 vs 7.63, p<0.05). Effect sizes were small (d=0.11), possibly due to the low socioeconomic status, diet diversity, and stimulation as well as high prevalence of stunting and access to iodized salt in some control areas that may have hampered greater benefits that iodine alone could provide. Grant Funding Source : Supported by Micronutrient Initiative, Canada