Developmental effects of micronutrient supplementation and malaria in Zanzibari children

Abstract

Background: Children's development is affected by the interplay of internal and external factors and changes in one factor can precipitate changes in multiple developmental domains.

Aims: The aim of this study was to test a theoretical model of children's development using structural equation modeling.

Study design: This was designed as a substudy of a randomized, placebo-controlled, 2 × 2 factorial trial of the effects of daily supplementation with iron (12.5 mg) + folic acid (50 μg) (FeFA) with or without zinc (10 mg) (Zn) on child mortality.

Subjects: Zanzibari children aged 5-9 mo (n = 106) and 10-14 mo (n = 141) at baseline were included in this sub study.

Outcome measures: Longitudinal data on children's hemoglobin, growth, malaria infection, motor development, motor activity, and language development and caregiver behavior were used to test the fit of the theoretical model for two age groups and to examine the direct and indirect relationships among the variables in the model.

Results: The theoretical models were a good fit to the data for both age groups and revealed that FeFA with or without Zn had positive effects on motor development. FeFA alone had negative effects on language development in both age groups and Zn alone had negative effects on language development in children aged 10-14 mo. The incidence of malaria had negative effects on the majority of health and development outcomes in children aged 5-9 mo, and on motor development and hemoglobin in children aged 10-14 mo.

Conclusions: These findings illustrate how nutrition and health factors can affect different domains of development and how these changes can precipitate changes in other domains. More work is needed to better understand the multiple impacts of internal and external factors on children's development and how changes in developmental domains interact with each other over time to determine children's overall developmental trajectory. The randomized, placebo-controlled study was registered as an International Standard Randomized Controlled Trial, number ISRCTN59549825.

Keywords: Africa; Anemia; CFI; Caregiver behavior; Child development; FeFA; FeFA+Zn; HAZ; Hb; ID; IDA; Iron supplementation; Malaria; NFI; SES; Structural equation modeling; Stunting; TMA; ZPP; Zinc supplementation; Zn; comparative fit index; height-for-age Z-score; hemoglobin; iron deficiency; iron deficiency anemia; iron+folic acid treatment group; iron+folic acid+zinc treatment group; normed fit index; socioeconomic status; total motor activity; zinc protoporphyrin; zinc treatment group.