What is the conversion of 1.49 mg/dl of magnesium to mEq/l?

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Magnesium Conversion: 1.49 mg/dL to mEq/L

1.49 mg/dL of magnesium equals approximately 1.23 mEq/L.

Conversion Formula and Calculation

To convert magnesium from mg/dL to mEq/L, you need to understand that magnesium is a divalent cation (Mg²⁺) with an atomic weight of 24.3 1.

The conversion formula is:

  • mEq/L = (mg/dL × 10 × valence) / atomic weight
  • mEq/L = (mg/dL × 10 × 2) / 24.3
  • mEq/L = mg/dL × 0.823

For 1.49 mg/dL:

  • 1.49 × 0.823 = 1.23 mEq/L

Alternatively, you can convert to mmol/L first using the conversion factor 0.411 1, then multiply by 2 (since magnesium is divalent):

  • 1.49 mg/dL × 0.411 = 0.612 mmol/L
  • 0.612 mmol/L × 2 = 1.22 mEq/L (essentially the same result)

Clinical Context

This magnesium level of 1.49 mg/dL (1.23 mEq/L) is below the normal range and represents hypomagnesemia 1.

  • Normal magnesium reference ranges vary by age, but for adults the typical range is approximately 1.7-2.4 mg/dL 1, 2
  • The Mayo Clinic guidelines define hypomagnesemia as magnesium <1.7 mg/dL 1
  • This level would be considered a modifiable risk factor requiring correction, particularly in patients at risk for cardiac arrhythmias 1

Clinical significance: At 1.49 mg/dL, this patient requires magnesium supplementation 1, 3. The route (oral vs. IV) and urgency depend on whether the patient is symptomatic, has cardiac risk factors, or is receiving QT-prolonging medications 1, 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Oral Magnesium Supplementation Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Treatment of Pediatric Hypomagnesemia

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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