Magnesium
Magnesium is the fourth most abundant mineral in the body, involved in over 300 enzyme reactions including ATP production, muscle and nerve function, and protein synthesis. Most magnesium is inside cells and bone — serum magnesium is a small fraction and may not reflect total body stores.
Normal Range
1.7–2.4 mg/dL
Reference ranges may vary slightly between laboratories. Always interpret your result in context with your doctor.
Why is Magnesium measured?
Magnesium is tested in unexplained low potassium or calcium (which often coexist with low magnesium), muscle cramps, arrhythmias, malabsorption disorders, and chronic alcohol use.
High Magnesium means…
High magnesium is rare in people with normal kidney function. Causes include kidney failure (with magnesium-containing antacids or laxatives), severe dehydration, and Addison's disease.
Low Magnesium means…
Low magnesium is common, especially in alcohol users, people on diuretics or proton pump inhibitors, and those with chronic diarrhoea. Symptoms overlap with low calcium and low potassium.
Symptoms associated with abnormal Magnesium
When Magnesium is high:
- Lethargy, weakness
- Low blood pressure
- Slow heart rate
- Respiratory depression in severe cases
When Magnesium is low:
- Muscle cramps and twitching
- Fatigue
- Nausea
- Heart palpitations or arrhythmia
- Tingling, numbness
How to improve your Magnesium
- Long-term PPI users (omeprazole, esomeprazole) should have magnesium checked periodically.
- Refractory hypokalaemia almost always requires magnesium replacement first.
- Dietary sources: leafy greens, nuts, seeds, whole grains, legumes.
Frequently asked questions about Magnesium
Can magnesium supplements help with sleep or cramps?
Magnesium supplementation has modest evidence for muscle cramps and possibly sleep quality in deficient individuals. Forms like magnesium glycinate or citrate are better absorbed than oxide.
Medical Sources
This page is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider about your individual results.