|EVIDENCE-BASED MEDICINE: SUMMARY OF STUDY
|Year : 2017 | Volume
| Issue : 2 | Page : 142-143
Zinc supplementation in diarrhea: Summary of cochrane database review
Tony Abraham Thomas
Christian Medical College, Vellore, Tamil Nadu, India
|Date of Web Publication||18-May-2017|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Thomas TA. Zinc supplementation in diarrhea: Summary of cochrane database review. Curr Med Issues 2017;15:142-3
Source: This is a summary of the Cochrane Database Review: Lazzerini M, Wanzira H. Oral zinc for treating diarrhea in children. Cochrane Database Syst Rev 2016;12:CD005436. Summary prepared by Dr. Tony Abraham Thomas, Christian Medical College, Vellore, Tamil Nadu, India.
Clinical Question: Is the oral supplementation of zinc along with oral rehydration solution useful in the treatment of diarrhea in children?
Authors' conclusions: (1) In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged 6 months or more. (2) The current evidence does not support the use of zinc supplementation in children <6 months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency.
| Background|| |
Zinc is necessary for cell division and growth, wound healing, and functioning of the immune system. It is a particularly important micronutrient in infants, growing children, adolescents, and pregnant/lactating mothers and these individuals constitute a high-risk group who are most vulnerable to zinc deficiency.,, Zinc is found in meat and fish products and also in plant products such as legumes, nuts, and whole-grain cereals (the absorption of plant-derived zinc is, however, inhibited by phytates). Zinc is not stored in the body, and regular dietary supplementation is vital to maintain adequate levels. About 50% of excretion of zinc occurs through the gastrointestinal tract and this is increased in diarrhea. There is, therefore, a risk of zinc deficiency in infants and young children with diarrheal diseases. The WHO and the United Nations Children's Fund  recommend supplementation of zinc for children under 5 years of age with diarrhea (10–20 mg of zinc per day), in addition to oral rehydration solution (ORS). Zinc is usually given as zinc sulfate, zinc acetate, or zinc gluconate, which are all water-soluble compounds.
How does the addition of zinc help? There are several mechanisms of action of zinc on acute diarrhea, some of which are specific to the gastrointestinal system: Zinc restores mucosal barrier integrity and enterocyte brush border enzyme activity, it promotes the production of antibodies and circulating lymphocytes against intestinal pathogens, and has a direct effect on ion channels, acting as a potassium channel blocker of adenosine 3-5-cyclic monophosphate-mediated chlorine secretion.
However, is the addition of zinc to ORS useful in diarrhea? The authors of this Cochrane Review set out to answer this question, to evaluate the usefulness of oral zinc supplementation for treating children with acute or persistent diarrhea.
| Results|| |
- Reducing deaths: There is currently not enough evidence from well-conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhea reduces death or number of children hospitalized (very low certainty evidence)
- Reducing duration of diarrhea: In children older than 6 months of age, zinc supplementation may shorten the average duration of diarrhea by around half a day (95% confidence interval [CI]: −19.72–−3.19; 2581 children, low certainty evidence), and probably reduces the number of children whose diarrhea persists until day 7 (risk ratio [RR]: 0.73, 95% CI: 0.61–0.88; 3865 children, six trials, moderate certainty evidence)
- In children with signs of malnutrition, there appears to be a greater effect; zinc supplementation reduced the duration of diarrhea by around a day (95% CI: −36.54–−16.23; high certainty evidence)
- Conversely, in children younger than 6 months of age, the available evidence suggests that zinc supplementation may have no effect on the mean duration of diarrhea (95% CI: −4.00–14.45; moderate certainty evidence), or the number of children who still have diarrhea on day 7 (RR: 1.24, 95% CI: 0.99–1.54, moderate certainty evidence)
- Adverse effects: None of the included trials reported serious adverse events. However, zinc supplementation increased the risk of vomiting in both age groups (children >6 months of age and children <6 months of age, and moderate certainty evidence).
In children with persistent diarrhea, zinc supplementation probably shortens the average duration of diarrhea by around 16 h (95% CI: −25.43–−6.24; moderate certainty evidence).
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Roohani N, Hurrell R, Kelishadi R, Schulin R. Zinc and its importance for human health: An integrative review. J Res Med Sci 2013;18:144-57.
International Zinc Nutrition Consultative Group (IZiNCG), Brown KH, Rivera JA, Bhutta Z, Gibson RS, King JC, et al.
International Zinc Nutrition Consultative Group (IZiNCG) technical document #1. Assessment of the risk of zinc deficiency in populations and options for its control. Food Nutr Bull 2004;25 1 Suppl 2:S99-203.
Lazzerini M, Wanzira H. Oral zinc for treating diarrhoea in children. Cochrane Database Syst Rev 2016;12:CD005436.
World Health Organization & United Nations Children's Fund. Clinical management of acute diarrhoea (WHO/FCH/CAH/04.07). Geneva, New York: World Health Organization & United Nations Children's Fund; 2004.