Zinc and vitamin A supplementation in Australian Indigenous children with acute diarrhoea: a randomised controlled trial

Objective: To evaluate the role of zinc and vitamin A supplementation in the recovery of Indigenous children hospitalised for acute diarrhoea. Design: A randomised controlled 2 by 2 factorial trial of supplementation with zinc and vitamin A. Setting and participants: Aboriginal children (aged < 11 years) hospitalised for acute diarrhoea at Alice Springs Hospital, Northern Territory, April 2001-July 2002. Main outcome measures: Duration of diarrhoeal illness; re-admission for diarrhoeal illness within 120 days. Results: Our study involved 392 Aboriginal children with 436 episodes of diarrhoea. Supplementation with zinc, vitamin A, or combined zinc and vitamin A had no significant effect on duration of diarrhoea or rate of re-admission compared with placebo. Median diarrhoea duration after starting supplementation was 3.0 days for the vitamin A and zinc supplemented and placebo groups (P values 0.25 and 0.69, respectively). The number of re-admissions did not differ significantly between those receiving vitamin A or zinc and the relevant placebo groups (relative risk [95% Cl], 1.2 [0.7-2.1] and 1.3 [0.8-2.1], respectively). Conclusion: Vitamin A and zinc supplementation may not be indicated for in-hospital management of acute diarrhoeal disease in Aboriginal children living in remote areas. This finding may not apply to children with malnutrition, for whom other studies suggest a benefit. Larger trials incorporating more comprehensive data on the vitamin A and zinc status as well as nutritional status of study populations might help to explain the different results in different populations.