Zinc-MNP Trial for Prevention of Diarrhea and Promotion of Linear Growth

Randomized, Double-blind, Community-based Efficacy Trial of Various Doses of Zinc in Micronutrient Powders or Tablets in Young, Bangladeshi Children

This is a randomized, double-blind, community-based efficacy trial of different doses, forms, and frequencies of zinc supplementation for the prevention of diarrhea and promotion of linear growth among children 9-11 months of age in Dhaka, Bangladesh.

Zinc is essential to support growth in young children especially for tissues undergoing rapid cellular differentiation and turnover, such as those in the immune system and gastrointestinal tract. Therapeutic zinc supplementation has been initiated in low-income countries as part of diarrhea treatment programs to support these needs for young children but, the effects of preventive supplemental zinc as a tablet or as a multiple micronutrient powder (MNP) on child growth and diarrheal disease are mixed and pose programmatic uncertainties. Thus, a randomized, double-blind community-based efficacy trial of five different doses, forms, and frequencies of preventive zinc supplementation vs. a placebo was designed for a study in children aged 9-11 months in an urban community in Dhaka, Bangladesh. The primary outcomes of this 24-week study are incidence of diarrheal disease and linear growth. Study workers will conduct in-home morbidity checks twice weekly; anthropometry will be measured at baseline, 12 weeks and 24 weeks. Serum zinc and other related biomarkers will be measured in a subsample along with an estimate of the exchangeable zinc pool size using stable isotope techniques in a subgroup. Therapeutic zinc will be provided as part of diarrhea treatment, in accordance with Bangladesh's national policy. Therefore, the proposed study will determine the additional benefit of a preventive zinc supplementation intervention.

Inclusion Criteria:

• 9-11 months of age
• Weight-for-length Z score >= -3 according to the 2006 World Health Organization Growth Standards
• Hemoglobin concentration > = 7.0 g/dL

Exclusion Criteria:

• Presence of severe acute malnutrition, defined as a WLZ <-3 and/or the presence of bipedal edema and/or mid-upper arm circumference <115 mm;
• Presence of severe anemia, defined as a hemoglobin concentration < 7.0 g/dL
• Congenital anomalies (e.g. cardiac defects, cleft lip or palate) or any other conditions that interfere with feeding;
• Chromosomal anomalies and other organic problems (e.g. jaundice, tuberculosis)
• Currently consuming MNPs with no intention of stopping