Zinc plays a part in the maintenance of epithelial and tissue integrity through promoting cell growth and suppressing apoptosis and through its underappreciated role as an antioxidant, protecting against free radical damage during inflammatory responses. Thus, in the case of diarrhoea, multiple functions of zinc may help to maintain the integrity of the gut mucosa to reduce or prevent fluid loss. Notably, these responses can occur within 48 hours, much more rapidly than the direct effects of zinc on cellular development. (8)


A number of randomized controlled trials have demonstrated significant reduction in the incidence and duration of acute and persistent diarrhea in zinc-supplemented children compared to their placebo-treated counterparts.(9, 10)


A pooled analysis of randomized, controlled trials of zinc supplementation performed in nine low-income countries in Latin America and the Caribbean, South and Southeast Asia, and the Western Pacific, demonstrated that supplemental zinc led to an 18% reduction in the incidence of diarrhea and a 25% reduction in the prevalence of diarrhea(11). While the pooled analysis did not find differences in the effect of zinc by age, baseline serum zinc status, presence of wasting, or sex, the relevance of zinc supplementation to various geographic regions of the world remained unclear.


Recent studies from Africa using zinc supplementation in young children indicate significant benefit on diarrhea burden indicating that the effect may be consistent across various geographical regions (12,13) and even if zinc is administered with oral rehydration solution.(14)


Recent studies in Bangladesh of using zinc in the treatment of diarrhea in a community setting have also demonstrated substantial reduction in concomitant use of antibiotics by health-care providers (15), thus suggesting that there may be additional benefits to the use of zinc in the treatment of diarrhea.


Zinc decreases the length and severity of the diarrhoea. Zinc being important for the child's immune system will help the child fight off new episodes of diarrhoea in the 2-3 months following treatment. Zinc also improves appetite and growth. Findings suggest that zinc supplementation given for 10-14 days lowers the incidence of diarrhoea in the following 2-3 months.(16)


New recommendations, formulated by UNICEF and WHO in collaboration with the United States Agency for International Development (USAID) and experts worldwide, take into account new research findings while building on past recommendations. Success in reducing death and illness due to diarrhoea depends on acceptance of the scientific basis and benefits of these therapies by governments and the medical community. It also depends on reinforcing family knowledge of prevention and treatment of diarrhoea, and providing information and support to families. WHO and UNICEF therefore have recommend daily 20 mg zinc supplements for 10-14 days for children with acute diarrhoea, and 10 mg per day for infants under six months old, to curtail the severity of the diarrhoeal episode and prevent further occurrences in the ensuing 2-3 months.