RBC Mg
A more accurate measure of true magnesium status than serum magnesium.
What is it
Red blood cell magnesium reflects intracellular magnesium stores and is considered more accurate than serum magnesium, which represents only a small fraction of total body magnesium.
Why it's measured
RBC magnesium has been studied as a marker of functional magnesium status in research on cardiovascular health, neuromuscular function, and sleep.
Reference range
Standard laboratory reference
4.2 – 6.8 mg/dL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Generally not clinically concerning.
Lower
Has been associated with neuromuscular symptoms, sleep disturbance, and cardiac arrhythmia susceptibility in research literature.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Used when functional magnesium deficiency is suspected and serum magnesium is unclear.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.