Pediatric Vitamin C Dosing Recommendations
Primary Dosing by Age
For infants up to 12 months of age, administer 15-25 mg/kg/day of vitamin C, and for children over 12 months, administer 80 mg/day. 1
This recommendation comes from the ESPGHAN/ESPEN/ESPR/CSPEN guidelines on pediatric parenteral nutrition, representing the most authoritative guidance for vitamin C dosing in children. 1
Age-Specific Dosing Algorithm
Infants (0-12 months)
- Preterm infants on parenteral nutrition: 15-25 mg/kg/day 1, 2, 3
- Term infants on parenteral nutrition: 15-25 mg/kg/day 1, 2, 3
- Healthy infants (oral intake): 20 mg/day is sufficient to prevent deficiency 4
Children (>12 months to 18 years)
- Standard dose: 80 mg/day for children on parenteral nutrition 1
- Healthy children over 5 years (oral intake): 25 mg/day minimum 5
- Upper safety limit for ages 4-8 years: 650 mg/day 5
Special Populations Requiring Higher Doses
Children with malnutrition: The same dosing applies (15-25 mg/kg/day for infants, 80 mg/day for older children), though severe deficiency may require higher therapeutic doses. 2
Children with inflammatory diseases: These patients require higher doses to maintain normal serum concentrations due to increased metabolic demands. 2
Children with chronic kidney disease: Limit to 100 mg/day maximum for CKD stages 1-4 (not on dialysis) to prevent oxalate accumulation. 3
Route of Administration Considerations
Parenteral Administration
- Administer vitamin C with lipid emulsions whenever possible to reduce peroxidation and limit vitamin loss. 3
- Storage requirements: Store vitamin C solutions at 2-8°C for up to 72 hours stability; at room temperature (25°C), vitamin C becomes unstable after 48 hours. 3
- Daily administration is preferred over intermittent dosing to avoid transient high levels and potential adverse effects. 1
Oral Administration
- Prioritize whole fruits over juice as natural food sources. 5
- Administer with food to enhance iron absorption, particularly beneficial in children with malnutrition or anemia. 2
Critical Safety Considerations
Absolute Contraindications
- Screen before administering: Hemochromatosis or iron overload conditions, G6PD deficiency, history of oxalate kidney stones, and severe renal dysfunction without dialysis support. 3
Adverse Effects to Monitor
- High doses (>2 g/day) can cause gastrointestinal disturbances. 2, 6
- Monitor for edema if using doses >1 g daily. 3
- Monitor electrolytes closely in patients with acute kidney injury or chronic kidney disease receiving kidney replacement therapy. 3
Important Pitfalls to Avoid
- Never exceed 10 times the dietary reference intake without proven severe deficiency. 3
- Do not use megadoses routinely as they carry potential toxicity risks without demonstrated benefit in healthy children. 5
- Low birth weight infants have less adaptive capacity to high or low vitamin C doses and may require specific vitamin preparations tailored for their needs. 3
Duration and Monitoring
Continue supplementation until nutritional status improves and dietary intake provides sufficient vitamin C (typically 5 servings of fruits and vegetables daily). 2
Routine monitoring of vitamin C concentrations is not recommended except in patients on long-term parenteral nutrition (weeks to months) where monitoring may be needed based on clinical indications. 1
Clinical Context
The evidence base for these recommendations is primarily expert opinion rather than high-quality trials, as acknowledged by the guidelines themselves. 1 However, these doses are based on preventing deficiency while maintaining adequate plasma levels (≥50 µmol/L) and have strong consensus support from major pediatric nutrition societies. 1