Prenatal and preschool micronutrient supplementation and behavioral outcomes in school aged children in Nepal - a cohort study.

Background: Few studies examine behavioral difficulties among children in low-income countries or the influence of early-life nutrition interventions.

Objective: We examined the effect of micronutrient supplementation done as part of two randomized trials during pregnancy or in early preschool age on behavioral outcomes among school-age children in rural Nepal.

Methods: Children 7-9 years of age were enrolled in a cohort follow-up study in which the Conners Rating Scale-Revised was administered to their parents and teachers. These children were offspring of participants in a cluster-randomized trial during pregnancy receiving daily iron-folic acid, iron-folic acid+ zinc or multiple micronutrients, compared with a control (all groups received vitamin A). These children between 12 and 35 months of age also received daily placebo, iron-folic acid, zinc alone, or iron-folic acid+zinc in a separate randomized trial. Factor analysis identified two attention deficit hyperactivity disorder (ADHD)-related behaviors for parent scores (hyperactivity/oppositional and inattention) and two for teacher scores (hyperactivity and inattention). Using mixed effects linear regression analysis, we analyzed the effect of early life supplementation on behavioral domains in schoolchildren (n=1255).

Results: Exposure to prenatal iron-folic acid resulted in lower oppositionality/hyperactivity and inattention scores in children assessed via parental ratings in both unadjusted and adjusted analysis. Iron-folic acid with zinc reversed the positive effect seen with iron-folic acid. Multiple micronutrient supplementation resulted in a lower oppositionality and/or hyperactivity score, using parent and teacher ratings in the adjusted analysis. All three supplement groups in the preschool trial reduced child inattention when assessed by parents. Based on teacher ratings, groups that had received iron-folic acid alone or with zinc during preschool had reduced scores of hyperactivity in both unadjusted and adjusted analysis.

Conclusion: Our study shows potential benefit of early life exposure to micronutrient supplementation for child related behavior outcomes in a South Asian setting where inadequate diets and nutrition deficiencies exist.