Review of high-dose intravenous vitamin C as an anticancer agent.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing preclinical mechanisms and uncontrolled clinical case series.
PubMed 24571058 · doi:10.1111/ajco.12173
What was done
This narrative review examined the historical context, pharmacokinetic differences between oral and intravenous administration, potential pro-oxidant mechanisms, and existing clinical evidence regarding high-dose intravenous vitamin C as an anticancer agent.
What was found
The abstract reports no quantitative measurements, effect sizes, or study counts. It notes that while previous randomized controlled trials using oral vitamin C failed to show survival benefit, intravenous administration achieves distinct pharmacokinetics. In vitro pro-oxidant activity via hydrogen peroxide generation has been proposed, but current clinical evidence for intravenous vitamin C relies on ambiguous case series without established correlation between plasma concentrations and clinical response.
Why it matters
The review outlines why historical negative trials using oral vitamin C cannot rule out the efficacy of intravenous administration, while emphasizing that therapeutic benefit remains unproven and should not be recommended outside clinical trials.
Limits
The review provides no systematic search methodology or primary quantitative data. Available clinical evidence is constrained to retrospective reports and uncontrolled case series lacking standardized prognostic factors and pharmacodynamic validation in vivo.
Cited by
- supports High doses of vitamin C taken continuously can act as a pro-oxidant rather than an antioxidant.