Is 100 mg of magnesium citrate daily a safe dose for children?

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Last updated: September 14, 2025View editorial policy

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Magnesium Citrate Dosing for Children

100 mg of magnesium citrate daily is generally safe for children, but dosing should be based on age and weight rather than using a fixed adult dose.

Appropriate Dosing Guidelines

According to FDA labeling for magnesium citrate preparations 1, dosing for children should be age-specific:

  • Children 6 to under 12 years: 3 to 7 fl oz (maximum 7 fl oz in 24 hours)
  • Children 2 to under 6 years: 2 to 3 fl oz (maximum 3 fl oz in 24 hours)
  • Children under 2 years: consult a doctor

Magnesium Requirements in Children

The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines provide specific recommendations for magnesium intake in children 2:

  • For parenteral nutrition, the recommended magnesium intake is based on age:
    • Preterm infants: Higher requirements
    • Term infants and children: 2-3 mg/kg/day

While these are parenteral guidelines, they provide insight into children's magnesium needs. The oral dose would need to be higher due to incomplete intestinal absorption.

Safety Considerations

Potential Risks

  • A case report documented fatal hypermagnesemia in a child who received unsupervised high doses of magnesium oxide as part of megavitamin/megamineral therapy 3. This highlights the importance of appropriate dosing and medical supervision.

Monitoring

  • For children on long-term magnesium supplementation, monitoring is essential:
    • Check baseline serum magnesium, potassium, and renal function before starting therapy
    • Follow-up serum magnesium levels should be checked 1-2 weeks after initiation
    • Periodic monitoring (every 3-6 months) is recommended for long-term supplementation 4

Renal Function

  • Magnesium is excreted renally, so it should be used with caution in patients with kidney disease 4
  • In children with impaired renal function, magnesium supplementation could lead to hypermagnesemia

Benefits of Appropriate Magnesium Supplementation

Some studies suggest magnesium supplementation may have benefits for certain conditions in children:

  • One study found that magnesium supplementation (200 mg/day for 6 months) in children with ADHD and documented magnesium deficiency showed significant decrease in hyperactivity 5

Practical Recommendations

  1. Verify need: Ensure magnesium supplementation is necessary (documented deficiency or clinical indication)

  2. Appropriate dosing:

    • For most children, start at the lower end of the recommended range
    • Adjust based on age, weight, and clinical response
  3. Monitor for side effects:

    • Gastrointestinal symptoms (diarrhea is most common)
    • Signs of hypermagnesemia (rare at appropriate doses)
  4. Regular follow-up:

    • Check magnesium levels periodically
    • Assess for symptom improvement and side effects

Conclusion

While 100 mg of magnesium citrate daily is likely safe for most children, it's important to adjust the dose based on the child's age, weight, and clinical needs. Medical supervision is recommended, especially for long-term use or in children with underlying health conditions.

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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