High Dose Vitamin C

Patients with chronic EBV treated with high-dose IV vitamin C (7.5-50g) showed significant reduction in EBV viral capsid antigen (VCA) antibody titers and marked improvement in fatigue, cognitive function, and overall well-being. The authors proposed that pharmacological ascorbate concentrations directly inhibit viral replication while simultaneously enhancing NK cell cytotoxicity against EBV-infected cells.

High-dose IV vitamin C produced sustained plasma ascorbate levels of 20-49 mM — concentrations that generate selective cytotoxicity against cancer cells through hydrogen peroxide production in cells with low catalase activity, while healthy cells with normal catalase were unaffected. The study demonstrated the pharmacological basis for IV vitamin C as adjunctive cancer therapy.

In a phase I/II trial, high-dose IV vitamin C combined with carboplatin/paclitaxel chemotherapy reduced chemotherapy-associated toxicity (neurotoxicity, hepatotoxicity, bone marrow suppression) while trends suggested enhanced tumor response. The authors demonstrated that pharmacological ascorbate selectively sensitizes cancer cells to chemotherapy while protecting normal tissue — supporting its role as an adjunctive therapy.

The CITRIS-ALI trial and follow-up analyses established that high-dose IV vitamin C in critically ill patients reduced organ failure scores and mortality at 28 days. The findings demonstrated that vitamin C's role extends beyond antioxidant support into active modulation of inflammatory cascades during acute systemic stress — validating pharmacological-dose IV ascorbate as a therapeutic, not just nutritional, intervention.

Landmark pharmacokinetic study demonstrated that oral vitamin C absorption is strictly capped by intestinal transporters, with plasma concentration plateauing at approximately 200 μM regardless of oral dose. IV administration bypasses this ceiling, achieving plasma concentrations of 10,000-25,000 μM — the range required for the selective pro-oxidant tumoricidal and antiviral effects seen with pharmacologic dosing. The findings provided the mechanistic justification for IV (rather than oral) high-dose vitamin C.