Magnesium: What Your Blood Level Does and Does Not Tell You

Serum magnesium is the standard test, but it reflects only about 1% of your body’s magnesium. Learn what your result means, typical ranges, and dietary sources.

Understand your magnesium in minutes

Upload your lab report and get a personalized explanation for every biomarker.

Analyze my report

What it is

Magnesium is a mineral involved in hundreds of enzyme reactions, including energy production, muscle relaxation, nerve signaling, and blood pressure regulation.

Roughly 99% of body magnesium sits inside bone and cells. The serum test measures the remaining 1%, which the body defends tightly, so a normal result does not rule out low stores.

Why it matters

Low magnesium can contribute to muscle cramps, palpitations, poor sleep, migraine, and low potassium or calcium that will not correct until magnesium is replaced.

High magnesium is uncommon and usually reflects reduced kidney clearance or heavy supplement or antacid use.

Typical reference ranges

Ranges vary by lab and individual circumstances. These are common adult reference ranges for orientation only.

GroupCommon range
Low< 1.7 mg/dL
Normal1.7–2.2 mg/dL
Optimal-leaning2.0–2.2 mg/dLSome clinicians prefer the upper half
High> 2.2 mg/dLCheck kidney function and supplement use

Not sure where your magnesium falls? Upload your lab report and Nodava marks it against the range for you.

See where you fall

Where it comes from

Pumpkin seeds, almonds, cashews, spinach and other leafy greens, black beans, dark chocolate, and whole grains are the richest food sources. Refining grains removes most of the magnesium.

What can move your result

Proton pump inhibitors, diuretics, alcohol, poorly controlled diabetes, chronic diarrhea, and malabsorption all deplete magnesium; kidney disease raises it.

Frequently asked questions

Can I be deficient with a normal serum magnesium?
Yes. The body pulls magnesium from bone and cells to keep blood levels steady, so mild depletion often looks normal.
Which magnesium supplement is best absorbed?
Glycinate and citrate are generally better absorbed and gentler than oxide, which is mostly used for constipation.
Does magnesium help sleep?
Evidence is modest but positive for some people, particularly if intake is low to begin with.

Get the full picture from your lab report

Magnesium is just one piece of the puzzle. Nodava explains every biomarker on your report, highlights what is out of range, and helps you track changes over time.

Upload my report

Related biomarkers