Given by vein at levels far above any oral dose, high-dose vitamin C is consistently safe and well tolerated in carefully screened people. Signals of better quality of life, less fatigue and nausea, and lower inflammation appear when added to standard care, but its ability to extend survival or change the course of cancer remains unproven. (Full Review)
| Marker | Target | Why |
|---|---|---|
| G6PD enzyme activity | Normal (non-deficient) | Screens hemolysis risk before treatment |
| Creatinine / eGFR | eGFR >60 mL/min | Detects kidney impairment that raises oxalate-injury risk |
| Plasma vitamin C | Peak ~15–20 mmol/L | Confirms the target pharmacological concentration is reached |
| Urine oxalate | Within normal limits | Monitors the oxalate load driving stone and kidney risk |
| Ferritin / iron studies | ~30–150 ng/mL | Identifies iron overload that vitamin C could worsen |
| Fasting glucose (venous lab) | 70–90 mg/dL | Tracks glucose safely without meter interference |
| CBC and haptoglobin | Stable hemoglobin; normal haptoglobin | Detects hemolysis if it occurs during treatment |
| Potassium | 4.0–4.5 mmol/L | Monitors electrolyte balance with large infusions and renal stress |
Cadence: Baseline, again within the first 1–2 weeks, then every 2–4 weeks during an active course; kidney function checked more often if impaired