Effect of zinc supplementation on observed activity in low socioeconomic Indian preschool children

Abstract

Objectives: To investigate whether supplementation of zinc in preschool children is associated with improvement in observed activity levels.

Methods: On 2 consecutive days, we performed 5-hour observations with momentary time sampling (instant activity every 10 minutes) in children selected from an ongoing double-blind, randomized trial of zinc supplementation. The study was conducted in Kalkaji, a low-socioeconomic urban population of New Delhi with high diarrheal incidence and rates of malnutrition. A total of 93 children (48 zinc and 45 control) 12 to 23 months of age from an ongoing community-based, randomized, controlled trial received supplements for at least 1 month before study; 71% had received supplementation for more than 120 days. Zinc gluconate (10 mg of elemental zinc) was given daily, with both zinc and control groups receiving vitamins A, B1, B2, B6, D3, and E and niacinamide in addition.

Results: Outcomes were percentages of time spent in each of five activity levels and two groups representing high and low movement and overall rating by two activity scores. Children in the zinc group spent 72% more time performing activities in the high-movement group. Among the zinc-supplemented children, the activity rating by the children's activity rating score was 12% higher and by the energy expenditure score was 8.3% higher than in the control group.

Conclusions: In conclusion, zinc supplementation, given along with selected vitamins, was associated with significantly greater activity levels in children. The relationship between the activity increase and locomotor development needs to be investigated, as do the long-term implications of zinc supplementation in terms of developmental status and school performance.