Overview

This complementary and alternative medicine (CAM) information summary provides an overview of the use of high-dose vitamin C (also known as ascorbate or L-ascorbic acid) as a treatment for people with cancer. This summary includes a brief history of early clinical trials of high-dose vitamin C; reviews of laboratory, animal, and human studies; and current clinical trials.

This summary contains the following key information:

• Vitamin C is an essential nutrient with antioxidant functions at normal physiologic concentrations.

• High-dose vitamin C has been studied as a treatment for cancer patients since the 1970s.

• Laboratory studies have reported that high-dose vitamin C has pro-oxidant properties and decreased cell proliferation in prostate, pancreatic, hepatocellular, colon, mesothelioma, and neuroblastoma cell lines.

• Two studies of high-dose vitamin C in cancer patients reported improved quality of life and decreases in cancer-related side effects.

• Studies of vitamin C combined with other drugs in cancer patients have shown mixed results.

• Intravenous vitamin C has been generally well tolerated in clinical trials.

Many of the medical and scientific terms used in this summary are hypertext linked (at first use in each section) to the NCI Dictionary of Cancer Terms, which is oriented toward nonexperts. When a linked term is clicked, a definition will appear in a separate window.

Reference citations in some PDQ CAM information summaries may include links to external Web sites that are operated by individuals or organizations for the purpose of marketing or advocating the use of specific treatments or products. These reference citations are included for informational purposes only. Their inclusion should not be viewed as an endorsement of the content of the Web sites, or of any treatment or product, by the PDQ Cancer CAM Editorial Board or the National Cancer Institute.