Impact of zinc supplementation on persistent diarrhoea in malnourished Bangladeshi children

To evaluate the impact of zinc supplementation on the clinical recovery and body weight of children with persistent diarrhoea, a randomized, double-blind, controlled trial was conducted in 190 children with persistent diarrhoea aged between 3 and 24 months. Children were randomly allocated to receive either zinc (20 mg d(-1)) syrup with multivitamin (2 x RDA) or multivitamin alone in three divided daily doses for 2 weeks. The trial was conducted in a diarrhoeal disease hospital in Dhaka, Bangladesh. Duration until clinical recovery (d), impact on body weight and serum zinc level after 2 weeks of zinc supplementation were recorded. The duration of illness was significantly reduced (33%) with zinc supplementation among children who were underweight (less than or equal to 70% wt/age, p = 0.03). Supplemented male children also had a significant reduction (27%) in duration for recovery compared with unsupplemented children (p = 0.05). From baseline to convalescence, zinc-supplemented children maintained their serum zinc concentration (13.4 vs 13.6 mu mol l(-1)), whereas unsupplemented children had a decrease in serum zinc after the 2 weeks of diarrhoea (13.6 vs 11.8 mu mol l(-1), p < 0.03). The mean body weight of the children in the supplemented group was maintained (5.72 vs 5.70 kg, p = 0.62) during hospitalization, unlike that of the control group, in which there was a reduction in body weight (5.75 vs 5.67 kg, p = 0.05). Five children in the unsupplemented group and one child in the zinc-supplemented group died during the 2 weeks of supplementation (p = 0.06). Zinc supplementation in persistent diarrhoea significantly reduced the length of the recovery period in malnourished children and prevented a fall in body weight and serum zinc concentration, indicating that zinc is a beneficial therapeutic strategy in this high-risk childhood illness.