RBC Magnesium
RBC magnesium measures the magnesium concentration inside red blood cells and more accurately reflects total body magnesium status than serum magnesium, which represents only a small fraction of body stores. Low levels are linked with fatigue, muscle cramps, arrhythmias, and insulin resistance, and occur with diuretics, alcohol use, and malabsorption.
1 providers include this
Electrolytes &Minerals
4.2-6.8 mg/dL
What is RBC Magnesium?
RBC magnesium measures the magnesium concentration inside red blood cells and more accurately reflects total body magnesium status than serum magnesium, which represents only a small fraction of body stores. Low levels are linked with fatigue, muscle cramps, arrhythmias, and insulin resistance, and occur with diuretics, alcohol use, and malabsorption.
Why It Matters
More accurate measure of total body magnesium status than serum magnesium. Deficiency is common and linked to fatigue, muscle cramps, and cardiovascular disease. Important for athletes and those on medications that deplete magnesium.
Which Providers Test RBC Magnesium?
Full Provider Comparison
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | — | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | — | $349 | 65 |
 Labcorp OnDemand | — | $398 | 40+ |
| — | $486 | 40+ | |
| — | $449 | 288 | |
| — | $349 | 100+ | |
| — | $829 | 54 | |
 Function Health | — | $365 | 160+ |
| ✓ | $250 | 65 | |
| — | $495 | 80+ | |
| — | $895 | 100+ | |
| — | $1950 | 130+ | |
| — | $375 | 95+ | |
| — | $Varies | 75+ | |
| — | $190 | 100+ | |
| — | $99 | 50 | |
| — | $124 | 60 | |
| — | $349 | 130+ | |
| — | $349 | 80+ | |
| — | $375 | 85 | |
| — | $700 | 128 | |
| — | $99 | 100+ |
Frequently Asked Questions
What is RBC Magnesium?
RBC magnesium measures the magnesium concentration inside red blood cells and more accurately reflects total body magnesium status than serum magnesium, which represents only a small fraction of body stores. Low levels are linked with fatigue, muscle cramps, arrhythmias, and insulin resistance, and occur with diuretics, alcohol use, and malabsorption.
What is the optimal range for RBC Magnesium?
The standard reference range for RBC Magnesium is 4.2-6.8 mg/dL. Optimal ranges may differ based on individual health goals and expert recommendations.
Which blood test providers include RBC Magnesium?
1 out of 22 blood testing providers include RBC Magnesium in their panels. This biomarker has limited availability.
What category does RBC Magnesium fall under?
RBC Magnesium is categorized under Electrolytes &Minerals. This category includes biomarkers that help assess related aspects of health and wellness.
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Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed:2026-04-12