This scoping review evaluated the potential harms associated with high-dose intravenous (IV) vitamin C therapy in adults by analyzing 74 studies involving 2,801 patients. High-dose vitamin C was defined as ≥6 g/day, ≥75 mg/kg/day, or ≥3 g/m²/day, with a median dose of 22.5 g/day (IQR: 8.25–63.75 g/day). At least 932
