High-Dose Vitamin C Infusions Increase Cancer Cell Sensitivity to Chemotherapy, Radiation
Researchers report that existing redox active compounds, like vitamin C, can sensitize cancer cells to radiation and chemotherapy.
Regular infusions of 800 to 1,000 times the recommended daily amount of vitamin C is safe in patients with brain or lung cancer, a report in Cancer Cell has shown.1
Researchers at the University of Iowa discovered a metabolic frailty in cancer cells that is based on cancer cells' production of oxidizing agents. Pathways that alter iron metabolism in cancer cells but not normal cells appear to lead to increased sensitivity to high doses of vitamin C, resulting in cancer cell death.
The researchers report that existing redox active compounds, such as vitamin C, can be utilized to sensitize cancer cells to radiation and chemotherapy.2
In this study, the researchers evaluated 11 patients enrolled in a brain cancer safety trial. Each patient received 3 infusions of vitamin C per week for 2 months followed by 2 infusions per week for 7 months while receiving standard care of radiation and chemotherapy. The goal of each infusion was to increase the concentration of vitamin C in the patient's blood from the level found in most adults (approximately 70 µM) to 20,000 μM.
The high dose is necessary because vitamin C has a half-life of approximately 2 hours in blood circulation in humans. The treatment was generally well tolerated, with modest side effects, such as frequent urination and dry mouth. Some patients developed hypertension that quickly subsided following infusion.
1. Schoenfeld JD, Sibenaller ZA, Mapuskar KA, et al. O2·- and H2O2-mediated disruption of Fe metabolism causes the differential susceptibility of NSCLC and GBM cancer cells to pharmacological ascorbate. Cancer Cell. 2017 Mar 30. doi: 10.1016/j.ccell.2017.02.018 [Epub ahead of print]
2. High doses of vitamin C to improve cancer treatment passes human safety trial. New York, NY: Cell Press; March 30, 2017. https://www.eurekalert.org/emb_releases/2017-03/cp-hdo032317.php. Accessed April 6, 2017.