In the late 1970s and again in the mid-1980s, the Mayo Clinic reported that high oral doses of vitamin C provided no benefit to patients with various types of advanced cancer. But Jeanne A. Drisko of the University of Kansas Medical Center thinks those findings did a disservice to the cancer community. Delivered orally, Drisko says, vitamin C reaches only micromolar concentrations in the bloodstream because of poor gut absorption and quick filtering by the kidneys. Intravenous vitamin C, on the other hand, achieves therapeutically useful millimolar blood concentrations, she notes. Not ready to give up on vitamin C, Drisko, Qi Chen, and colleagues administered vitamin C intravenously with the chemotherapy drugs paclitaxel and carboplatin to 10 patients with advanced ovarian cancer. Members of this group experienced fewer chemotherapy side effects than patients given only paclitaxel and carboplatin. They also had a slightly higher five-year survival rate (Sci. Transl. Med. 2014, DOI: 10.1126/scitranslmed.3007154). The researchers believe vitamin C is a prooxidant capable of generating reactive oxygen species that damage cancer cells but are deflected by healthy cells. They hope the results of this small study will drum up support for larger clinical trials to prove vitamin C’s worth as a cancer therapy.