Zinc Dosing for Pediatric Diarrhea
For children 6 months to 5 years of age with diarrhea, give 20 mg of elemental zinc daily for 10-14 days; for infants under 6 months, give 10 mg daily for 10-14 days. 1, 2
Age-Based Dosing Algorithm
Children 6 months to 5 years:
- 20 mg elemental zinc daily for 10-14 days 1, 2, 3
- This recommendation applies specifically to children in countries with high zinc deficiency prevalence or those with signs of malnutrition 1
- The evidence shows this reduces diarrhea duration by approximately 12-27 hours and increases recovery rates 4, 5, 3
Infants under 6 months:
- 10 mg elemental zinc daily for 10-14 days 2
- Note that zinc supplementation is NOT routinely recommended for healthy infants under 6 months except in the specific context of treating diarrhea in zinc-deficient populations 4
- Subgroup analyses show no benefit in children under 6 months in well-nourished populations 5
Clinical Context and Indications
The 2017 IDSA guidelines provide a strong recommendation with moderate evidence that zinc supplementation reduces diarrhea duration specifically in children who: 1
- Reside in countries with high prevalence of zinc deficiency, OR
- Have signs of malnutrition
In well-nourished children in developed countries, the benefit is less clear and zinc may not be routinely indicated. 5
Administration Considerations
- Zinc should be given for the full 10-14 day course, even after diarrhea resolves, to prevent recurrence over the subsequent 2-3 months 2
- For optimal absorption, zinc is ideally given between meals rather than with food 6
- Avoid administering with foods high in phytates, which reduce absorption 6
Expected Outcomes
Meta-analyses demonstrate that zinc supplementation results in: 5, 3
- Shorter diarrhea duration (mean reduction of 12-13 hours)
- Higher proportion of children recovered by day 3 (31% relative reduction), day 5 (45% relative reduction), and day 7 (29% relative reduction)
- Reduced severity of persistent diarrhea (mean reduction of 15.84 hours)
Important Adverse Effect
Vomiting is significantly more common with zinc supplementation (71% increased risk), occurring in approximately one-third of children 5, 3
- This is dose-dependent, with lower-dose zinc (10 mg) causing 20% fewer vomiting episodes compared to higher doses (20 mg) 3
- Despite increased vomiting, no serious adverse events have been reported 5
- Recent evidence suggests that modified formulations may improve tolerability, with 93% of children tolerating zinc well 7
Critical Pitfall to Avoid
Do not use zinc as a substitute for oral rehydration therapy - rehydration remains the cornerstone of diarrhea management 1, 8