High dose, intravenous (IV) vitamin C has been used as a complementary cancer treatment for many years but we still need more studies to show safety, efficacy, and who benefits the most. A recent small study (Phase 1 clinical trial) in 11 adults with brain cancer to determine if IV doses of vitamin C helped them. Patients also received chemotherapy and radiation. Phase 1 clinical trials aim to find out very basic information about a treatment, mainly if it is safe and how high of a dose humans can tolerate; it doesn't mean a treatment is ready to be used for everyone or that it will end up being helpful. The people in this vitamin C trial lived 4-6 months longer than the typical survival time of people with the same kind of brain cancer, 14-16 months.
While this is good news for future studies involving intravenous vitamin C, it unfortunately doesn't mean you'll be able to find this treatment readily available. If you are interested in learning more about vitamin C therapy, make sure to talk to your oncologist. If you seek out IV treatment, make sure the practitioner is appropriately trained (has extensive training and experience working with people who have cancer) and licensed. Taking high doses of oral vitamin C - capsules, tablets, or powders - will not have the same effect as the body can only absorb a certain amount at one time, far less than the amount that can be given by IV. High doses of oral vitamin C are generally safe but exceeding the amount you can absorb at one time will cause diarrhea.