Recommended Magnesium Supplementation Dosages for Children
For children requiring magnesium supplementation, the recommended dosages are age-specific: 0.1-0.2 mmol/kg/day (2.4-5 mg/kg/day) for infants 0-6 months, 0.15 mmol/kg/day (4 mg/kg/day) for infants 7-12 months, and 0.1 mmol/kg/day (2.4 mg/kg/day) for children 1-18 years. 1
Age-Specific Magnesium Dosing Guidelines
The ESPGHAN/ESPEN/ESPR/CSPEN guidelines provide clear recommendations for magnesium supplementation in children based on age:
| Age | Magnesium Dosage |
|---|---|
| Preterm infants (first days) | 0.1-0.2 mmol/kg/day (2.5-5.0 mg/kg/day) |
| Growing premature infants | 0.2-0.3 mmol/kg/day (5.0-7.5 mg/kg/day) |
| 0-6 months | 0.1-0.2 mmol/kg/day (2.4-5 mg/kg/day) |
| 7-12 months | 0.15 mmol/kg/day (4 mg/kg/day) |
| 1-18 years | 0.1 mmol/kg/day (2.4 mg/kg/day) |
For specific formulations like magnesium citrate, the FDA-approved dosing is:
- Children 2 to under 6 years: 2-3 fl oz daily (maximum 3 fl oz in 24 hours)
- Children 6 to under 12 years: 3-7 fl oz daily (maximum 7 fl oz in 24 hours)
- Children 12 years and over: 6.5-10 fl oz daily (maximum 10 fl oz in 24 hours) 2
Clinical Considerations for Magnesium Supplementation
Indications for Supplementation
- Magnesium supplementation should primarily be considered for documented hypomagnesemia
- Not routinely recommended as a sleep aid in children due to insufficient safety data 3
- May be beneficial in specific conditions such as ADHD, where studies have shown improvements with 200 mg/day supplementation in magnesium-deficient children 4
Monitoring Requirements
- Regular monitoring of serum magnesium levels is essential when supplementing
- For children on long-term supplementation, monitor:
Safety Concerns
- Fatal hypermagnesemia has been reported with unsupervised high-dose magnesium supplementation in children 5
- Children have immature renal function compared to adults, increasing the risk of magnesium accumulation 3
- Excess magnesium can cause vasodilation, hypotension, bradycardia, and CNS depression 3, 6
Special Populations
Preterm Infants
- Require careful monitoring of magnesium levels
- Higher dosages (0.2-0.3 mmol/kg/day) may be needed for growing premature infants 1
- If the mother received magnesium therapy before delivery, the infant's magnesium intake should be adjusted based on postnatal blood concentrations 1
Children with Medical Conditions
- For children with ADHD and documented magnesium deficiency, 200 mg/day has shown benefit in reducing hyperactivity 4
- In children with renal impairment, dosages should be reduced and levels monitored more frequently
- For children with cardiac conditions, careful monitoring is essential as magnesium affects cardiac conduction 6
Administration Considerations
- Oral magnesium supplements should be taken with a full glass of water
- May be given as a single daily dose or divided doses 2
- Magnesium is better absorbed when taken with food
- Different magnesium salts have varying bioavailability (magnesium citrate and glycinate are generally better absorbed than oxide)
Remember that magnesium supplementation should only be initiated when clinically indicated and with appropriate monitoring to prevent adverse effects, particularly in pediatric populations where safety margins may be narrower.