Impact of zinc supplementation on subsequent morbidity and growth in Bangladeshi children with persistent diarrhoea.

This study was conducted to explore whether supplementation of zinc to children during persistent diarrhoea has any subsequent effect on morbidity and growth. A prospective follow-up study was conducted among children, aged 3-24 months, with persistent diarrhoea, who participated earlier in a double-blind randomized placebo-controlled trial. During persistent diarrhoea, children were randomly allocated to receive either zinc in multivitamin syrup or only multivitamin syrup for two weeks. After recovering from diarrhoea, 76 children in the multi-vitamin syrup and 78 children in the zinc plus multivitamin syrup group were followed up for subsequent morbidity and growth. Weekly morbidity and two-weekly anthropometric data were collected for the subsequent 12 weeks. Data showed that episodes and duration of diarrhoea were reduced by 38% and 44% respectively with supplementation of zinc. There was no significant difference in the incidence or duration of respiratory tract infection between the zinc-supplemented and the non-supplemented group. Improved linear growth was observed in underweight children (weight-for-age <70% of the National Center for Health Statistics standard) who received zinc compared to those who did not receive.

Impact of zinc deficiency on vibrio cholerae enterotoxin-stimulated water and electrolyte transport in animal model.

The effect of zinc deficiency on the function of the intestine to absorb water and electrolytes was studied in animal models, stimulated by Vibrio cholerae enterotoxin. Sprague-Dawley rats, used in the study, were divided into four groups: Zinc-deficient, ad libitum zinc-fed control, zinc weight-matched control, and zinc-deficient acutely-repleted. 14C-labelled polyethylene glycol solution was used for measuring the absorption capacity of the small intestine. Significantly lower absorption of water and sodium per cm of the intestine was observed in the zinc-deficient animals compared to the ad libitum zinc-fed control animals (p < 0.01). An improved absorption capacity was equally observed in the zinc-deficient acutely-repleted animals and ad libitum zinc-fed control group. The zinc-deficient animals showed four times greater cholera toxin-induced net secretions of water and sodium compared to the ad libitum zinc-fed group (p < 0.01), while a 40% reduction was observed in the zinc-deficient acutely-repleted group. The results suggest that zinc deficiency is associated with reduced absorption of water and electrolytes and increased secretion of the same stimulated by cholera toxin.