Vitamin C IV — Supplements
High-dose intravenous ascorbic acid achieving pharmacologic plasma concentrations for adjunctive therapy.
Overview
High-dose intravenous vitamin C (IVC) achieves plasma concentrations 100-300 times higher than maximal oral dosing, enabling pharmacologic (rather than nutritional) effects. At these concentrations, vitamin C generates hydrogen peroxide selectively in the extracellular space of tumors and acts as a pro-oxidant against cancer cells while sparing normal tissue. Clinical trials in cancer patients show improved quality of life and reduced chemotherapy side effects. In critical care, the CITRIS-ALI and other trials showed mixed results for sepsis and ARDS, with some endpoints favoring IVC.
Indications
- Adjunctive cancer therapy (quality of life improvement)
- Severe vitamin C deficiency (scurvy) when oral not feasible
- Critical illness and sepsis support (investigational)
- Immune system support (acute illness)
Mechanism of Action
IV administration achieves plasma concentrations unattainable orally (>20 mmol/L vs. <0.3 mmol/L)
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Vitamin C (IV) | 25 g | 1-2 times weekly | 4-8 week course; screen for G6PD deficiency first; dose range 15-75 g/session |
Evidence Grade
GRADE C
Safety & Contraindications
- Screen for G6PD deficiency before administration (hemolytic anemia risk)
- May cause osmotic diuresis, hyponatremia, or calcium oxalate nephropathy
- Infusion-related effects: flushing, headache, nausea, thirst
- Can interfere with point-of-care glucose monitors (false readings)
- Must be administered by healthcare professional in a clinical setting