Nutrition, Growth and Health in Tanzanian Infants

Abstract

Undernutrition in early life increases children’s risk of mortality, morbidity, and impaired growth and development. This thesis analyzes data from two randomized controlled trials in Dar es Salaam, Tanzania. The first trial assessed the effect of daily multivitamin (vitamins B-complex, C and E) supplementation on mortality and morbidity in infants born to HIV-infected mothers. 2387 infants were randomized to multivitamins or placebo at 6 weeks and followed-up for two years. The second trial assessed the effect of zinc and/or multivitamins (vitamins B-complex, C and E) on morbidity in infants born to HIV-uninfected mothers. 2400 infants were randomized to either zinc + multivitamins, zinc only, multivitamins only, or placebo at 6 weeks and were followed for 18 months.

Chapter 1 assesses the effect of zinc and/or multivitamin supplements in the second trial on longitudinal child growth – defined by change in height-for-age, weight-for-age and weight-for-height z-scores (HAZ, WAZ and WHZ) and stunting, underweight and wasting (<-2 SD 2006 WHO standard for each indicator respectively). We found small, but significant effects of supplements on change in WHZ and WAZ, but did not find a statistically significant effect of zinc and/or multivitamin supplements on stunting, wasting or underweight.

Chapter 2 assesses the effect of zinc and/or multivitamin supplements in the second trial on early child development (ECD) assessed using the cognitive, motor (fine and gross) and language (receptive and expressive) scales of the Bayley Infant Scales of Development 3rd Edition (BSID-III). We did not find a significant effect of supplements on early childhood development as assessed by the BSID-III.

Chapter 3 pools the two trials in order to compare mortality, morbidity and growth in HIV-infected, HIV-exposed-but-uninfected (HIV-EU) and HIV unexposed infants. HIV-infected children had the highest rates of mortality, morbidity and growth failure. HIV-EU infants had higher rates of mortality and morbidities than unexposed infants; but lower rates than their HIV-infected peers.

Conclusions: Alternative approaches (beyond zinc and/or multivitamin supplementation) to improve growth and ECD in vulnerable populations should be pursued. Child health interventions should target not only HIV-infected but also HIV-EU children, given their increased susceptibility to morbidity and mortality.