A new study published in Cancer Cell researchers found in clinical studies that it was safe to regularly infuse brain and lung cancer patients with 800 to 1,000 times the daily recommended amount of vitamin C as a potential strategy to improve outcomes of standard cancer treatments. In addition, they showed pathways by which altered iron metabolism in cancer cells, and not normal cells, lead to increased sensitivity to cancer cell death caused by high dose vitamin C.
In the study 11 patients enrolled in the brain cancer safety trial and received three infusions of vitamin C a week for 2 months followed by two infusions per week for 7 months while receiving standard care of radiation and chemotherapy. The goal of each infusion was to raise the concentration of vitamin C in a patients blood to 20,000 uM, as compared to a blood level of 70 uM found in most adults. A high dose is necessary because vitamin C has a half life of around two hours in circulating human blood. The treatment was generally well tolerated except for frequent trips to the bathroom and dry mouth. (as an aside, dry mouth was the one symptom mentioned by Dr Francisco Contreras at the Oasis of Hope where they have used high dose vitamin C with cancer patients). Researchers found that occasionally patients had elevated blood pressure that subsided quickly following infusion.
The safety of the high dose vitamin C is due to the fact that it is not toxic to normal cells but when interacting with cancer cells the high levels of redox active iron molecules in the cancer cells reacts with the vitamin C to form hydrogen peroxide and free radicals formed from hydrogen peroxide. The free radicals are believed to cause DNA damage selectively in the cancer cells that lead to cancer cell death and sensitivity to radiation and chemotherapy in cancer cells. (This has been long known by alternative doctors who use the high dose vitamin C without the chemo and radiation). Researchers said “This is a significant example of how knowing details of potential mechanisms and the basic science of redox active compounds in cancer versus normal cells can be leveraged clinically in cancer therapy.” …Here , we verified convincingly, that increased redox active metal ions in cancer cells were responsible for the differential sensitivity of cancer versus normal cells to very high doses of vitamin C.” Further studies on safety and vitam C are planned.