What is the recommended dose of zinc (Zn) syrup for an 8-year-old child weighing 31 kilograms (kg)?

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Recommended Zinc Dosage for an 8-Year-Old Child Weighing 31kg

For an 8-year-old child weighing 31kg, the recommended zinc syrup dosage is 50 μg/kg/day, which equals 1.55 mg/day (not exceeding the maximum of 5 mg/day for routine supplementation). 1, 2

Dosage Calculation and Rationale

  • According to Clinical Nutrition guidelines, children older than 12 months should receive zinc supplementation at a dose of 50 μg/kg/day up to a maximum of 5 mg/day for routine supplementation 1
  • For this 8-year-old child weighing 31kg, the calculation is: 31kg × 50 μg/kg/day = 1,550 μg/day or 1.55 mg/day 2
  • This dosage is well below the maximum recommended limit of 5 mg/day, making it appropriate and safe for routine supplementation 1

Administration Recommendations

  • Zinc syrup should be administered as directed by the manufacturer 2
  • For optimal absorption, zinc supplements should ideally be given between meals rather than with food 2
  • Avoid administering zinc with foods high in phytates (found in grains, legumes), which can reduce absorption 2

Special Considerations

  • If the child has diarrhea or increased gastrointestinal fluid losses, higher doses of zinc may be required 1, 2
  • For acute diarrhea, lower doses (5-10 mg) have shown similar efficacy to the standard 20 mg dose with fewer side effects like vomiting 3
  • In cases of zinc deficiency, therapeutic doses of 0.5-1 mg/kg per day may be given for 3-4 months 2

Clinical Importance and Monitoring

  • Zinc is an essential nutrient involved in metabolism of energy, proteins, carbohydrates, lipids, and nucleic acids 1
  • Zinc deficiency in children can lead to stunted growth, increased risk of infections, and characteristic skin rash 1
  • Regular zinc supplementation may help prevent episodes of diarrhea and improve growth slightly in children 4
  • For children on long-term zinc supplementation, monitor serum zinc levels and alkaline phosphatase periodically 1, 2

Potential Side Effects

  • Higher doses of zinc may cause vomiting, nausea, and other gastrointestinal symptoms 3, 4
  • Co-supplementation of zinc with iron may decrease the beneficial effect of zinc 4
  • Organic zinc compounds may have better tolerability than inorganic forms 2

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Zinc Supplementation Guidelines for Children

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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