| Property | Magnesium | Zinc |
|---|---|---|
| Scientific name | Mg citrate / glycinate / oxide | Zinc gluconate / picolinate |
| Safety rating | Generally Safe | Conditionally Safe |
| Evidence level | Strong | Strong |
| Category | Major Minerals | Trace Minerals |
| RDA | 420 mg (M) / 320 mg (F) | 11 mg (M) / 8 mg (F) |
| Tolerable UL | 350 mg (suppl.) | 40 mg |
| Clinical pearl | Subclinical deficiency affects up to 30% of the general population [2]. Serum magnesium is a poor marker (only 1% of body stores) — consider RBC magnesium or ionized magnesium for accurate assessment [1]. Glycinate form preferred for tolerability and sleep; citrate for cost-effectiveness. Start 200 mg, titrate upward — loose stools indicate absorptive capacity exceeded [2]. | Zinc lozenges (gluconate or acetate, 75 mg/day total) started within 24 hours of cold onset reduce duration by approximately one-third [2]. Chronic supplementation above 40 mg/day induces copper deficiency — co-prescribe 1–2 mg copper if using high doses long-term [1]. Vegetarians require 50% more dietary zinc due to phytate inhibition [1]. Avoid zinc nasal sprays (permanent anosmia risk). |
| Key interactions | See profile | See profile |
| US products (DSLD) | 6,209 | 3,209 |