Recommended Zinc Dosage for Treating Diarrhea
For children 6 months to 5 years of age with diarrhea, the recommended zinc dosage is 20 mg of elemental zinc daily for 10-14 days, while infants under 6 months should receive 10 mg of elemental zinc daily for 10-14 days. 1, 2
Age-Based Dosing Recommendations
Infants and Young Children
- Under 6 months: 10 mg elemental zinc daily for 10-14 days 2, 3
- 6 months to 5 years: 20 mg elemental zinc daily for 10-14 days 1, 3
Special Populations
- Children with malnutrition: Particularly important to provide zinc supplementation as recommended above 1
- Children in areas with high zinc deficiency prevalence: Follow standard dosing as above 1
Evidence Supporting Zinc Supplementation
The Infectious Diseases Society of America (IDSA) strongly recommends zinc supplementation for children with diarrhea (strong, moderate evidence) 1. This recommendation is based on multiple studies showing that zinc supplementation:
- Reduces the duration of diarrhea in children 1
- Decreases the severity of diarrheal episodes 3
- Can provide protection against future episodes for up to 2-3 months 3
A meta-analysis found that zinc supplementation resulted in:
- Greater proportion of children recovering from diarrhea (RR = 1.07; moderate certainty of evidence) 4
- Reduction in diarrhea duration by approximately 13 hours (moderate certainty of evidence) 4
Administration Guidelines
- Zinc should be given along with oral rehydration solution (ORS) for maximum benefit 2
- Continue normal feeding and breastfeeding throughout the diarrheal episode 1, 2
- Human milk feeding should be continued in infants and children throughout the diarrheal episode (strong recommendation) 1
- Resumption of age-appropriate usual diet is recommended during or immediately after the rehydration process 1
Recent Evidence on Lower Dosing
Recent research suggests that lower doses of zinc (5-10 mg) may be equally effective with fewer side effects:
- A 2020 randomized controlled trial found that 5 mg and 10 mg doses were non-inferior to 20 mg for treating childhood diarrhea 5
- Lower doses were associated with significantly less vomiting (a common side effect of zinc supplementation) 5, 4
- Vomiting occurred in 19.3% of children receiving 20 mg zinc compared to 15.6% with 10 mg and 13.7% with 5 mg 5
Important Considerations and Precautions
- Do not use antimotility drugs (e.g., loperamide) in children under 18 years with acute diarrhea 1, 2
- Do not discontinue breastfeeding during diarrheal episodes 1, 2
- Do not neglect rehydration - zinc supplementation is an adjunct to, not a replacement for, proper hydration with ORS 1, 2
- Zinc supplementation appears to be more effective in children with stunted growth or signs of malnutrition 6
- The effect of zinc may be more pronounced after 3 days of supplementation 6
Conclusion for Clinical Practice
While the standard recommended dose remains 20 mg for children 6 months to 5 years and 10 mg for infants under 6 months, clinicians should be aware that recent evidence suggests lower doses (5-10 mg) may be equally effective with fewer side effects, particularly vomiting. The full 10-14 day course should be completed regardless of symptom resolution to provide potential protection against future episodes.