Vitamin C, an essential nutrient often supplemented to prevent colds and support longevity, helps build collagen and aids antioxidant defenses. Correcting low intake is well supported; regular supplements slightly shorten colds, modestly lower blood pressure and ease exercise-related airway narrowing. Long trials in well-nourished adults showed no longer life, fewer heart attacks or less cancer. Risks at usual doses are low, mainly kidney stones in men on high doses. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Plasma vitamin C (fasting) | 50–80 µmol/L | Expected to change; confirms status |
| Home blood pressure | No established target; change from own one-week baseline average | Expected to change |
| HbA1c (people with diabetes) | 4.0–5.6% | Expected to change in type 2 diabetes |
| Serum uric acid | Men 3.4–7.0 mg/dL; women 2.4–6.0 mg/dL | Expected to change |
| Serum creatinine with eGFR | Men 0.74–1.35 mg/dL; women 0.59–1.04 mg/dL | Safety check; reduced function stops high doses |
| Ferritin and transferrin saturation | Ferritin men 24–336 ng/mL, women 11–307 ng/mL; saturation 20–50% | Safety check; high values stop high doses |
| 24-hour urinary oxalate (stone history) | Below 40 mg/24 h | Safety check; rising values reduce dose |
| G6PD activity (before infusions) | Normal enzyme activity | Safety check; deficiency stops infusions |
Cadence: Baseline panel before starting; repeat plasma vitamin C and blood-pressure average 8–12 weeks after a dose change; kidney function, iron status and uric acid every 6–12 months on gram doses; kidney function rechecked before each new intravenous course