Vitamin C (Ascorbic Acid) for Antioxidant Support

Research suggests that vitamin C may offer antioxidant benefits through several mechanisms, including reducing oxidative stress markers and, in one cell and animal study, potentially lowering levels of ACE2 — the protein SARS-CoV-2 uses to enter cells — by promoting its degradation. The available evidence for this application comes largely from preclinical and observational sources, including animal models, retrospective observational studies, and systematic reviews, with few rigorous human trials directly testing vitamin C's antioxidant effects in isolation. A systematic review on nutrition and COVID-19 found mechanistic and observational evidence that addressing nutritional deficiencies is important for immune function, but stopped short of recommending high-dose supplementation due to insufficient evidence, and a comparative animal study found that vitamin C was outperformed by lycopene and proanthocyanidin in several antioxidant measures. Taken together, the research is mixed and largely preliminary, and while vitamin C's role as an antioxidant is biologically plausible and supported by some experimental findings, stronger human trial evidence would be needed to draw firm conclusions about its practical value for antioxidant support.