Magnesium
Mineral involved in 300+ biochemical reactions
15 of 22 providers
Electrolytes &Minerals
muscle function
What is Magnesium?
Magnesium is the fourth most abundant mineral in your body and is involved in over 300 enzymatic reactions, including energy production (ATP synthesis), DNA/RNA synthesis, protein synthesis, muscle and nerve function, blood pressure regulation, and glucose control. About 50-60% of your body's magnesium is stored in bones, 25% in muscles, and only 1% circulates in blood. This means serum magnesium (measured in standard blood tests) is a poor marker of total body magnesium status—you can be significantly deficient with "normal"serum magnesium.
Here's the critical insight:magnesium deficiency is epidemic. An estimated 50-75% of Americans don't meet the RDA for magnesium (420 mg/day for men, 320 mg/day for women), and up to 20% have overt deficiency. Modern agricultural practices have depleted soil magnesium, reducing food magnesium content by 30-50% over the past century. Processed foods, stress, alcohol, certain medications (PPIs, diuretics), and chronic diseases all further deplete magnesium. Yet magnesium deficiency is rarely diagnosed because serum magnesium doesn't drop until severe depletion—by the time serum magnesium is low, you're critically deficient.
Red blood cell (RBC) magnesium or ionized magnesium are more sensitive tests of intracellular magnesium status, but they're not routinely available. A better approach:if you have symptoms of magnesium deficiency (muscle cramps, insomnia, anxiety, arrhythmias, constipation) and normal serum magnesium, trial supplementation with 300-400 mg/day magnesium for 2-3 months. Most people benefit, and magnesium toxicity is rare with normal kidney function (excess is excreted).
Why Magnesium Matters for Longevity
- Energy production:Magnesium is required for ATP synthesis in mitochondria. Every ATP molecule must be bound to magnesium to be biologically active. Deficiency causes fatigue.
- Cardiovascular health:Magnesium relaxes blood vessels, lowers blood pressure, prevents arrhythmias. Deficiency increases risk of hypertension, atrial fibrillation, sudden cardiac death, heart attacks.
- Insulin sensitivity and glucose control:Magnesium is a cofactor for insulin receptors. Deficiency causes insulin resistance, type 2 diabetes. Low magnesium associated with 2-3x higher diabetes risk.
- Bone health:50-60% of body magnesium is in bones. Magnesium is required for vitamin D activation, calcium regulation, and bone formation. Deficiency increases osteoporosis risk.
- Muscle and nerve function:Magnesium regulates neuromuscular transmission and muscle contraction. Deficiency causes cramps, spasms, tremors, restless legs, migraines.
- Sleep and stress resilience:Magnesium activates GABA receptors, promoting relaxation and sleep. Deficiency causes insomnia, anxiety, stress intolerance.
- Inflammation:Magnesium has anti-inflammatory effects. Deficiency raises CRP and pro-inflammatory cytokines, accelerating aging.
Optimal vs Standard Ranges
Optimal (Longevity)2.2-2.6 mg/dL (serum)▼
- Upper-normal range associated with better cardiovascular and metabolic health
- Many functional medicine doctors target >2.2 mg/dL
Adequate (Standard)1.8-2.2 mg/dL▼
- Meets standard guidelines but may be suboptimal
- Consider supplementation if symptoms (cramps, insomnia, anxiety) despite normal serum level
Low-Normal (Suboptimal)1.5-1.8 mg/dL▼
- Low-normal serum magnesium
- Likely indicates tissue magnesium depletion
- Supplement with 300-400 mg/day elemental magnesium
Deficient<1.5 mg/dL▼
- Frank magnesium deficiency
- Serum magnesium rarely drops this low unless severe depletion or renal wasting
- Requires aggressive magnesium replacement (oral or IV)
Scientific Evidence
Serum magnesium <1.8 mg/dL is suboptimal but tissue deficiency can exist with "normal"serum levels. RBC magnesium is more sensitive.
Muscle weakness, fatigue|Nausea, vomiting|Hypotension (low blood pressure)|Bradycardia (slow heart rate)|Flushing, warmth|Loss of deep tendon reflexes|Respiratory depression (if severe)|Cardiac arrest (if very severe, >7 mg/dL)
Low dietary intake:Standard American diet provides only 250-300 mg/day (RDA is 320-420 mg). Processed foods, refined grains depleted of magnesium.|Soil depletion:Modern agriculture has reduced magnesium in crops by 30-50% over past 50-100 years.|Malabsorption:Celiac disease, Crohn's disease, chronic diarrhea, gastric bypass, chronic pancreatitis.|Medications:PPIs (omeprazole), diuretics (furosemide), antibiotics (aminoglycosides), chemotherapy (cisplatin).|Alcohol abuse:Increases urinary magnesium excretion and impairs absorption.|Type 2 diabetes:Hyperglycemia causes osmotic diuresis, wasting magnesium in urine.|Chronic stress:Cortisol and adrenaline increase urinary magnesium loss.|Aging:Absorption decreases and urinary losses increase with age.|Chronic kidney disease (moderate):Impaired reabsorption of magnesium.
Kidney failure (end-stage renal disease):Kidneys can't excrete magnesium, causing accumulation.|Excessive IV magnesium:Iatrogenic (medical error) or pre-eclampsia treatment.|Massive oral intake:Laxative abuse (milk of magnesia, Epsom salt ingestion). Requires >5000 mg/day with normal kidney function.|Rare:Hypothyroidism, Addison's disease (reduce renal excretion).
Magnesium Deficiency Prevalence
~50% of Americans consume less than the RDA for magnesium (420 mg men, 320 mg women). Up to 20% have overt deficiency based on dietary surveys. Serum magnesium underestimates true prevalence because it's tightly regulated;tissue depletion occurs first.
Magnesium and Cardiovascular Disease
Magnesium deficiency is associated with hypertension, arrhythmias, coronary artery disease, and sudden cardiac death. Meta-analyses show magnesium supplementation (300-400 mg/day) lowers systolic BP by 3-5 mmHg and diastolic BP by 2-3 mmHg. Higher dietary magnesium intake associated with 30% lower CVD risk.
Source:Zhang X, et al. Effects of magnesium supplementation on blood pressure:a meta-analysis. Hypertension. 2016;68(2):324-333.
Magnesium and Type 2 Diabetes
Low magnesium intake and serum levels strongly associated with insulin resistance and type 2 diabetes (2-3x higher risk). Magnesium is required for insulin receptor function and glucose transport. Magnesium supplementation (300-400 mg/day) improves insulin sensitivity, fasting glucose, and HbA1c in diabetics and prediabetics.
Source:Larsson SC, Wolk A. Magnesium intake and risk of type 2 diabetes:a meta-analysis. J Intern Med. 2007;262(2):208-214.
Which Providers Test Magnesium?
Full Provider Comparison
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | ✓ | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | — | $349 | 65 |
 Labcorp OnDemand | — | $398 | 30+ |
| ✓ | $486 | 40+ | |
| ✓ | $444 | 288 | |
| ✓ | $349 | 100+ | |
| ✓ | $761 | 54 | |
 Function Health | ✓ | $365 | 160+ |
| ✓ | $250 | 65 | |
| ✓ | $495 | 70+ | |
| ✓ | $895 | 100+ | |
| ✓ | $1950 | 150+ | |
| ✓ | $375 | 80+ | |
| — | $Varies | 75+ | |
| ✓ | $190 | 100+ | |
| — | $99 | 50 | |
| — | $124 | 60 | |
| — | $199 | 50 | |
| ✓ | $499 | 120+ | |
| — | $4188 | 70-80+ | |
| ✓ | $375 | 85 | |
| ✓ | $700 | 128 |
Frequently Asked Questions
What is Magnesium?
Mineral involved in 300+ biochemical reactions
What is the optimal range for Magnesium?
The standard reference range for Magnesium is muscle function. Optimal ranges may differ based on individual health goals and expert recommendations.
Which blood test providers include Magnesium?
15 out of 22 blood testing providers include Magnesium in their panels. This biomarker is widely available across major providers.
What category does Magnesium fall under?
Magnesium is categorized under Electrolytes &Minerals. This category includes biomarkers that help assess related aspects of health and wellness.
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:2026-02-20