Systematic Review of Intravenous Ascorbate in Cancer Clinical Trials.
Level 3 - non-randomized controlled study
Systematic review of predominantly non-randomized and single-arm Phase I/II trials
PubMed 30002308 · doi:10.3390/antiox7070089
What was done
Authors systematically searched PubMed, MEDLINE, and Cochrane databases for single-arm and randomized Phase I/II clinical trials evaluating the safety and clinical efficacy of intravenous (IV) ascorbate alone or with chemotherapy across various cancer types. Study selection was conducted by three authors and results were synthesized narratively.
What was found
23 trials comprising 385 total patients met inclusion criteria. IV ascorbate was reported to be safe alone and in combination with chemotherapy in nearly all patient populations. Only 1 of the 23 trials was randomized (evaluating ovarian cancer receiving chemotherapy with or without vitamin C); that trial reported an 8.75-month increase in progression-free survival and an improved trend in overall survival in the ascorbate arm. Quantitative efficacy data for the remaining 22 trials were not reported in the abstract.
Why it matters
High-dose IV ascorbate has a documented safety profile in early-phase oncology settings, but controlled clinical evidence of efficacy remains extremely sparse.
Limits
22 of the 23 included trials were non-randomized single-arm Phase I/II studies, making efficacy conclusions vulnerable to confounding. The total sample size across all 23 studies was small (385 patients, averaging ~17 patients per trial), and only one randomized trial was available.
Cited by
- supports The most commonly reported side effects of intravenous vitamin C administration are mild to moderate nausea, headache, and dry mouth, while less common side effects include fatigue, hypertension, loss of appetite, and hyperglycemia.
- supports Clinical studies of high-dose intravenous vitamin C in cancer patients have not reported impairments in kidney function.