Magnesium bound to the amino acid glycine, chosen for a gentler effect on the bowel than cheaper forms — a real advantage, though thinly evidenced. Blood pressure, blood sugar, sleep and mood improve mainly in people starting low or already treated; in adults eating well, the same doses move very little. Magnesium-rich food, not capsules, tracks with living longer. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Serum magnesium | 0.85–0.95 mmol/L | Only routinely available index of magnesium status |
| Red blood cell magnesium | 4.2–6.8 mg/dL | Reflects stores inside cells, which serum does not |
| Estimated glomerular filtration rate | ≥90 mL/min/1.73 m²; ≥60 acceptable | Kidneys clear all excess magnesium; the safety gate |
| Serum potassium | 4.0–4.5 mmol/L | Magnesium depletion causes potassium loss that will not correct |
| Serum calcium (albumin-adjusted) | 9.2–9.8 mg/dL | Depletion suppresses parathyroid hormone and lowers calcium |
| Parathyroid hormone | 15–35 pg/mL | Detects the hormonal consequence of depletion |
| 25-hydroxyvitamin D | 40–60 ng/mL | Cofactor for every vitamin D activating enzyme |
| Glycated haemoglobin | ≤5.4% | Tracks the glucose benefit where one exists |
| Home blood pressure | <120/80 mmHg | The best-quantified benefit; needs its own baseline |
Cadence: Blood magnesium, potassium, calcium and creatinine at 8–12 weeks, then every 6–12 months; earlier checkpoint and annual testing thereafter on diuretics, proton pump inhibitors or with reduced kidney filtration.