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OBJECTIVES: To assess the effect of zinc supplementation on growth and body composition among schoolchildren. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING AND SUBJECTS: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls), 11–17 y). INTERVENTIONS: Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study. VARIABLES: Weight, height, upper arm circumference, triceps skinfold thickness, and weight-for-age, height-for-age, weight-for-height, arm muscle-area-for-age and arm fat-area-for-age Z-scores. RESULTS: Significant effects on weight gain (0.51 vs 0.14 kg, P=0.01), weight-for-age Z (-0.08 vs -0.14, P=0.01) and arm muscle area-for-age Z-score (0.10 vs 0.01, P=0.03) were seen over the first three months, whereas no effects were seen over the full 12 months. CONCLUSIONS: Zinc deficiency impairing lean body mass and weight gain was documented. However, the effect of zinc seen over the first three months vanished during the last nine months when the food programme was in operation. Zinc deficiency may have persisted, but another nutrient may have become growth limiting during the last nine months. SPONSORSHIP: Danish International Development Assistance. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To assess the effect of zinc supplementation on susceptibility to S. mansoni reinfections among schoolchildren. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING AND SUBJECTS: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls), 11–17 y). INTERVENTIONS: Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study. OUTCOME MEASURES: S. mansoni and S. haematobium reinfection rates and intensities. RESULTS: There was no difference in reinfection rates between the zinc and placebo groups (25 vs 29%, P=0.46). However, the median intensity of S. mansoni reinfection, although low in both groups, was significantly lower in the zinc than in the placebo group (7 vs 13 eggs per gram of faeces, P=0.048). No difference in either S. haematobium reinfection rates or intensities were seen. CONCLUSIONS: Zinc supplementation reduced the intensity of S. mansoni reinfections. Although the intensities of reinfection were very low, the finding probably reflects a biological effect of zinc that could be of public health importance in settings with higher transmission. SPONSORSHIP: Danish International Development Assistance. [ABSTRACT FROM AUTHOR]

Objective: To study the relation between indicators of infection and Schistosoma mansoni and S. haematobium infection, and serum concentrations of zinc, ferritin and retinol., Design: Cross-sectional., Setting and Subjects: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls, 11-17 years)., Variables: S. mansoni and S. haematobium egg output, concentration of C-reactive protein, neutrophil count, questionnaire data on fever and diarrhoea, and serum concentrations of retinol, ferritin and zinc., Results: Age, elevated CRP, fever and S. mansoni egg output were significant predictors of the concentration of retinol. The regression coefficient for age was positive, and negative for elevated CRP, fever and S. mansoni egg output. As S. mansoni, but not S. haematobium, was of significance, it is unlikely that low retinol level increased susceptibility to infection. The effect of S. mansoni on retinol level was 0.03 mumol/l (95% CI: 0.002-0.06, P = 0.03) for each 100 eggs/g increase in egg output. Neither indicators of infection nor age and sex were predictors of concentration of zinc and log10 concentration of ferritin., Conclusion: S. mansoni infection reduced retinol level, when indicators of infection and age were controlled for. High intensities of S. mansoni infection may induce vitamin A deficiency among children with marginal vitamin A status. The study emphasizes the importance of controlling for age and metabolic response to concurrent infections in studies using serum retinol as a measure of vitamin A status.