Effectiveness of Micronutrient Powders (MNP) in women and children

More than 3.5 million women and children under five die each year in poor countries due to underlying undernutrition. Many of these are associated with concomitant micronutrient deficiencies. In the last decade point of use or home fortification has emerged to tackle the widespread micronutrient deficiencies. We in this review have estimated the effect of Micronutrient Powders (MNPs) on the health outcomes of women and children.

We systematically reviewed literature published up to November 2012 to identify studies describing the effectiveness of MNPs. We used a standardized abstraction and grading format to estimate the effect of MNPs by applying the standard Child Health Epidemiology Reference Group (CHERG) rules.

We included 17 studies in this review. MNPs significantly reduced the prevalence of anemia by 34% (RR: 0.66, 95% CI: 0.57-0.77), iron deficiency anemia by 57% (RR: 0.43, 95% CI: 0.35-0.52) and retinol deficiency by 21% (RR: 0.79, 95% CI: 0.64, 0.98). It also significantly improved the hemoglobin levels (SMD: 0.98, 95% CI: 0.55-1.40). While there were no statistically significant impacts observed for serum ferritin and zinc deficiency. Our analysis shows no impact of MNPs on various anthropometric outcomes including stunting (RR: 0.92, 95% CI: 0.81, 1.04), wasting (RR: 1.13, 95% CI: 0.91, 1.40), underweight (RR:0.96, 95% CI: 0.83, 1.10), HAZ (SMD: 0.04, 95% CI: -0.13, 0.22), WAZ (SMD: 0.05, 95% CI: -0.12, 0.23) and WHZ (SMD: 0.04, 95% CI: -0.13, 0.21), although showing favorable trends. MNPs were found to be associated with significant increase in diarrhea (RR: 1.04, 95% CI: 1.01, 1.06) with non-significant impacts on fever and URI.

Our analysis of the effect of MNPs in children suggests benefit in improving anemia and hemoglobin however the lack of impact on growth and evidence of increased diarrhea requires careful consideration before recommending the intervention for implementing at scale.