The Effect of Vitamin C (Ascorbic Acid) in the Treatment of Patients with Cancer: A Systematic Review.
Level 2 - randomized trial
Systematic review of mixed study designs (only 4 of 19 included trials were randomized)
PubMed 31035414 · doi:10.3390/nu11050977
What was done
The authors conducted a systematic review using PubMed and EMBASE to evaluate the effectiveness and safety of vitamin C (ascorbic acid) administration in cancer patients. All study designs except Phase I studies and case reports were included. Assessed outcomes included overall survival, clinical status, quality of life (QOL), and performance status (PS).
What was found
A total of 19 trials were included, with only 4 being randomized placebo-controlled trials. The abstract provides no quantitative data or effect sizes. The authors found no proof of a clinically relevant positive effect on overall survival, clinical status, QOL, or PS in general cancer patients due to the low quality of published studies. Intravenous administration appeared more effective than oral, and vitamin C treatment was safe with minimal side effects.
Why it matters
This review highlights that current evidence does not substantiate routine vitamin C supplementation for improving oncology outcomes, pointing to a need for rigorous randomized trials in defined patient subsets.
Limits
Only 4 of the 19 included trials were randomized controlled trials, and overall study quality was low. Interventions and patient populations were highly heterogeneous, and the abstract reports no specific numerical effect estimates, sample sizes of participants, or risk metrics.
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.