A new study suggests giving some cancer patients high doses of vitamin C intravenously - rather than orally - together with conventional chemotherapy, may help destroy cancer cells and reduce some of its detrimental side effects. Published in Science Translational Medicine, researchers from the University of Kansas Medical center found that using vitamin C, along with two conventional chemotherapy drugs, stopped ovarian cancer in the lab.

Injected vitamin C could potentially be a safe, effective, and low-cost treatment for ovarian and other cancers, according to the researchers. Injection ascorbate – or vitamin C - has been used as an alternative therapy for cancer since the 1970s. When clinical trials of vitamin given by mouth failed to yield the same results, the research was abandoned.

The researchers enrolled 27 patients were recently diagnosed with stage 3 or stage 4 ovarian cancer. Each patient underwent conventional chemotherapy with paclitaxel or carboplatin, but some also received high doses of vitamin C intravenously. They were then monitored for 5 years. 

Patients who had intravenous vitamin C along with the conventional chemotherapy drugs had fewer toxic effects than people who did not intake vitamin C. 

In a similar experiment, the researchers found that vitamin C destroyed cancer cells in mice with ovarian cancer. This was only achieved if the vitamin C was given intravenously. No observable detrimental changes were found in the mouse liver, kidney, or spleen.

When looking at the function of vitamin C at the molecular level, they found that vitamin C surrounds the tumor cells, stimulates creation of hydrogen peroxide, which kills cancer cells. 

“We aimed to investigate the mechanisms of vitamin C-induced cell death in the laboratory. And in patients with ovarian cancer, we conducted an early phase clinical trial examining safety and toxicity of high dose intravenous vitamin C. We now have a better understanding of vitamin C’s anti-cancer action, plus a clear safety profile, and biological and clinical plausibility with a firm foundation to proceed,” Dr. Drisko says.

Funding for large clinical trials of intravenous vitamin C is difficult because pharmaceutical companies are unlikely to be interested. Vitamin C is a natural substance; therefore, it cannot be patented.

Additional Resource:

High-Dose Parenteral Ascorbate Enhanced Chemosensitivity of Ovarian Cancer and Reduced Toxicity of Chemotherapy