To “C” Or Not To “C:” Can High Dose Vitamin “C” Impact Side Effects of Chemotherapy?

To “C” Or Not To “C:” Can High Dose Vitamin “C” Impact Side Effects of Chemotherapy?

by Vicky Rego, Breast Cancer Helpline Coordinator

I recently had the opportunity to attend the Breast Cancer Options Integrative Medicine conference at SUNY New Paltz, where there were several workshops discussing topics such as risk and recurrence reduction, medical marijuana in treatment and care, a report back from San Antonio lead by Dr. Sheldon Feldman, stress reduction, nutrition, the financial impact of cancer, and moving beyond BRCA genetic testing. It’s difficult to determine which of the workshops I attended stood out, but one topic stood out as potentially being new information.

Ronald Stram M.D. is the founder and director of the Stram Center for Integrative Medicine. Dr. Stram’s presentation "Reducing Risk and Recurrence, and Treating the Underlying Cause of Breast Cancer" was an informative discussion on topics from cell function and disruptions in cell function that lead to cancer cells, to epigenetic changes needed for cell survival: proliferation, differentiation, cell death and expression of cell type function. Dr. Stram discussed unexpected commonalities between infection and cancer, stating that “25% of all cancers have a known infection or infection associated chronic inflammation.” He also spoke about various integrative treatments used at the Stram Center, such as FMT (fecal microbiota transplants), anti-inflammatory diets (with much praise to the Mediterranean diet), free radicals and antioxidant flavonoid rich diets (drink more green tea), the use of turmeric, hyperbaric oxygen therapy, and acupuncture. While all of this had the audience listening, his discussion on vitamin C stood out because we are typically told not to take vitamin C supplements during treatment. Which lead several members of the audience asking why we’re told to stay away.

While many of us are told not to take supplements, Dr. Stram discussed research that shows high dose IV Vitamin C infusions, given in conjunction with chemotherapy, has positive outcomes with reduction of side effects. He discussed hydrogen peroxide, a pro-oxidant created in the breakdown of vitamin C that is capable of causing free radical damage. The enzyme catalase deactivates hydrogen peroxide, allowing the normal cell to keep its antioxidant effect. But since tumor cells lack catalase, cancer cells are left vulnerable to free radical damage from hydrogen peroxide by selectively taking up vitamin C, accumulating it to higher levels than normal cells. High doses of Vitamin C can therefore be harmless (or even beneficial) to normal cells, but at the same time, kill tumor cells. Also, since IV vitamin C creates a pro-oxidant effect, it is unlikely to counteract the effect of chemotherapy. When asked how much is needed, Dr. Stram said 5-6 grams is enough, more would cause adverse side effects such as diarrhea.

This presentation led me to more research. While some studies do show benefits of high dose IV vitamin C treatments used in conjunction with chemotherapy, that research is focus on ER-positive disease. We must keep in mind that this treatment is not right for everyone; it can have adverse effects when used with some chemotherapies, and on those with other medical conditions such as kidney disease. The other issue is that, while studies show positive results, the FDA has not approved the use of high dose vitamin C or the use of any supplements. The manufacturing of supplements is not regulated as pharmaceutical manufacturing is. Perhaps more research can provide enough positive responses, and the FDA will consider approving this co-therapy.


Cell Press. (2017, March 30). High doses of vitamin C to improve cancer treatment passes human safety trial. ScienceDaily. Retrieved May 13, 2019 from

Ma, Y., Chapman, J., Levine, M., Polireddy, K., Drisko, J., & Chen, Q. (2014). High-dose parenteral ascorbate enhanced chemosensitivity of ovarian cancer and reduced toxicity of chemotherapy. Science translational medicine, 6(222), 222ra18-222ra18.

Megan Garlapow, P. (2017, January 27). High Doses of Vitamin C Kill Cancer Cells in Culture. Retrieved from OncologyNurseAdvisor:

National Cancer Institute. (2019, January 19). High-Dose Vitamin C (PDQ®)–Patient Version. Retrieved from National Cancer Institute:

Vollbracht, C., Schneider, B., Leendert, V., Weiss, G., Auerbach, L., & Beuth, J. (2011). Intravenous vitamin C administration improves quality of life in breast cancer patients during chemo-/radiotherapy and aftercare: results of a retrospective, multicentre, epidemiological cohort study in Germany. in vivo, 25(6), 983-990

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