No evidence to support use of vitamin C supplementation in cancer

the Oncology Nurse Advisor take:

According to a new study published in the journal The Oncologist, researchers have found that there is no high-quality evidence to support the use of ascorbate (vitamin C) supplementation to enhance efficacy or reduce toxicity of chemotherapy in patients with cancer.

For the systematic review, researchers from the Ottawa Hospital Cancer Centre Division of Medical Oncology in Ottawa, Ontario, Canada, sought to investigate whether supplemental ascorbate synergizes the anticancer effects of chemotherapy and reduces its toxicity.

Researchers identified 34 articles to be included in the study from Medline, EMBASE, and the Cochrane central register. Among those, there were five randomized controlled studies, 12 phase 1/2 studies, six observational trials, and 11 case reports.

The studies included a total of over 8,000 patients. Results showed no statistically significant improvements in overall survival or progression-free survival or reduced toxicity with supplemental ascorbate use compared with the control arm.

The authors note that high-quality placebo-controlled studies are needed to assess the effects of ascorbate on chemotherapy efficacy and toxicity in patients with cancer.