Magnesium for Toddlers
Age-Specific Dosing for Toddlers (1-3 years)
For toddlers requiring parenteral nutrition, provide 0.1 mmol/kg/day (2.4 mg/kg/day) of magnesium, as recommended by ESPGHAN/ESPEN guidelines. 1, 2
Parenteral Nutrition Context
- Toddlers aged 1-18 years on parenteral nutrition should receive 0.1 mmol/kg/day (2.4 mg/kg/day) of magnesium 1, 3
- This dosing ensures optimal growth and bone mineralization while preventing both deficiency and toxicity 1
- Use magnesium sulfate rather than magnesium chloride to avoid increasing anion gap and risk of metabolic acidosis 1
- Regular monitoring of serum magnesium, calcium, phosphorus, and alkaline phosphatase is required 1
Oral Magnesium Supplementation
For oral magnesium citrate in toddlers aged 2 to under 6 years, the FDA-approved dosing is 2-3 fl oz in 24 hours (maximum 3 fl oz in 24 hours). 4
- Organic magnesium salts (aspartate, citrate, lactate) have better bioavailability than inorganic forms 3
- Always administer with a full glass (8 ounces) of liquid 4
- Most magnesium salts are poorly absorbed and may cause diarrhea, requiring monitoring and potential formulation adjustment 5
Emergency/Acute Indications
Life-Threatening Arrhythmias
- For torsades de pointes, administer 25-50 mg/kg IV/IO (maximum 2 g) 2, 5
- Give as rapid bolus for pulseless torsades 2
- Infuse over 10-20 minutes for torsades with pulses 2, 5
Severe Asthma/Status Asthmaticus
- Administer 25-50 mg/kg IV (maximum 2 g) over 15-30 minutes for refractory status asthmaticus 2, 5
- Common adverse effects include flushing (2.2%) and sedation (0.4%) 2
Critical Safety Considerations
Contraindications and Precautions
- Avoid magnesium supplementation if creatinine clearance <20 mL/min due to high risk of life-threatening hypermagnesemia 5
- Magnesium produces vasodilation and may cause hypotension if administered rapidly 5
- Monitor for signs of toxicity: hypotension, bradycardia, respiratory depression, and loss of deep tendon reflexes 5
- Have calcium chloride immediately available (20 mg/kg or 0.2 mL/kg of 10% solution IV) to reverse magnesium toxicity 2
Special Population: Maternal Magnesium Exposure
- For neonates/infants exposed to maternal magnesium therapy, limit magnesium intake and adjust based on postnatal serum concentrations 1, 2, 3
- These infants may have elevated magnesium levels in the first days of life and limited ability to excrete excess magnesium 1
Gastrointestinal Losses
- In toddlers with diarrhea or high gastrointestinal losses, correct sodium and water depletion first before initiating magnesium supplementation 5
- This addresses secondary hyperaldosteronism, which increases renal magnesium wasting 5
Monitoring Requirements
- Regular monitoring of serum magnesium, calcium, phosphorus, and alkaline phosphatase concentrations 1
- For long-term parenteral nutrition, periodic monitoring of calcium, phosphorus, vitamin D, and bone mineral status (e.g., DEXA) to assess for metabolic bone disease 1
- Monitor urine calcium and phosphorus concentrations 1
Common Pitfalls to Avoid
- Never use unsupervised high-dose magnesium supplementation - fatal hypermagnesemia has been reported in children receiving megavitamin/megamineral therapy without medical supervision 6
- Avoid acidic solutions packaged in glass vials (e.g., calcium gluconate) as they are contaminated with aluminum 1, 3
- Do not administer magnesium rapidly in non-emergency situations due to risk of hypotension 5
- Excessive supplementation can worsen diarrhea, potentially increasing magnesium loss 5, 3