Mineral
Magnesium
Magnesium requires 320 mg daily for adult women and 420 mg for men. The tolerable upper intake level is 350 mg from supplements. It has 2 severe interactions, notably with Magnesium oxide and Magnesium glycinate.
What Magnesium does
Cofactor in 300+ enzyme reactions including ATP handling, and a natural calcium channel blocker.
The UL applies to supplemental magnesium only. Glycinate and citrate are well absorbed.
How much you need
| Measure | Adult male | Adult female |
|---|---|---|
| Recommended intake | 420 mg | 320 mg |
| Upper intake level | 350 mg (supplemental only) | |
| Typical supplement dose | 200-400 mg elemental · 200-400 mg elemental | |
Interactions involving Magnesium
9 sourced rules| Pair | Severity | Mechanism | Action |
|---|---|---|---|
| Magnesium oxide × Tetracycline antibioticseparate 3h | Severe | Divalent cations chelate tetracyclines in the gut to form non-absorbable complexes, which can cut antibiotic absorption by more than half. | Separate magnesium and tetracyclines by at least 2 hours before or 4-6 hours after the antibiotic dose.Source |
| Magnesium glycinate × Fluoroquinolone antibioticseparate 3h | Severe | Magnesium binds fluoroquinolones in the gut and can reduce absorption by up to 60%, risking treatment failure. | Take the antibiotic at least 2 hours before or 6 hours after magnesium.Source |
| Magnesium oxide × Levothyroxineseparate 4h | Moderate | Magnesium salts bind levothyroxine and reduce its absorption when taken at the same time. | Leave at least 4 hours between levothyroxine and magnesium.Source |
| Magnesium glycinate × Alcohol | Moderate | Alcohol increases renal magnesium excretion and impairs absorption, worsening magnesium depletion; sedative effects also add. | Avoid taking magnesium with alcohol. Separate by several hours and do not use it to offset drinking.Source |
| Calcium citrate × Magnesium glycinateseparate 2h | Mild | High-dose calcium and magnesium share absorptive pathways and compete to a modest degree; the interaction is only meaningful at large supplemental doses. | If you take more than 500 mg of either, separate them by about 2 hours. Small doses together are fine.Source |
| Zinc picolinate × Magnesium glycinateseparate 2h | Mild | Zinc and magnesium compete weakly for absorption. Clinical impact is small unless both are taken in large doses at once. | No change needed at typical doses. If you take 30 mg+ zinc, separate it from magnesium by 2 hours.Source |
| Potassium citrate × Magnesium glycinate | Mild | Both are cations handled by overlapping renal and intestinal transport; combined high doses can add to electrolyte shifts. | Take them at separate times and monitor if you have kidney disease or take diuretics.Source |
| Magnesium glycinate × ACE inhibitor | Mild | Magnesium supplements can add a small blood-pressure-lowering effect and, at high doses in renal impairment, raise serum magnesium. | Typical doses are fine. Discuss with your prescriber if you have reduced kidney function.Source |
| Vitamin B6 (P5P) × Magnesium glycinate | Synergy | Pyridoxal-5-phosphate increases cellular magnesium retention, so the two work better together than either alone. | Taking B6 with magnesium is well tolerated and may improve magnesium status.Source |