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High-Dose Vitamin C for Cancer Reconsidered

New evidence that high-doses intravenous (IV) vitamin C may be associated with cancer remission is prompting reassessment of this treatment approach. A Canadian Medical Association Journal report summarizes three case studies that suggest IV vitamin C may hold potential as an anti-cancer therapy.

The article by Sebastian Padayatty, MD, of the National Institute of Diabetes and Digestive and Kidney Diseases, and colleagues was also reported by MedPage Today on March 27, 2006.

The authors note that Vitamin C is considered an "alternative cancer therapy because early controlled clinical trials did not confirm clinical benefit, and that these case studies support the "clinical plausibility" that vitamin C offers therapeutic benefit:

"A key distinction between conventional, science-based medicine and alternative therapy is the presence or absence of scientific plausibility¦. Many treatments are still used if there is moderately good, albeit inconclusive evidence of efficacy (clinical plausibility)."

Vitamin C taken intravenously raises plasma levels substantially higher than oral vitamin C therapy (14,000 micromoles per liter versus a maximum of 220 micromoles per liter, respectively). At the higher concentrations in vitro, vitamin C is toxic to some cancer cells, but not to normal cells, a finding that supports vitamin C's therapeutic effectiveness.

Clinical Trials

Although early studies of high-dose vitamin C (administered orally or IV) suggested benefit, because a subsequent controlled trial " using only oral vitamin C " failed to confirm this finding, the treatment was considered ineffective.

Dr Padayatty and colleagues present three case studies of people with cancer who had poor prognoses followed by an unusually favorable outcome. The researchers contend that, while the results are inconclusive, they "were analyzed in accordance with the National Cancer Institute's Best Case Series process, which reports and interprets apparent responses to alternative therapies."

First case study. The first case study involved a 51-year-old woman with renal cell carcinoma that metastasized. Refusing conventional anti-cancer therapy, she chose to receive high-dose IV vitamin C (65 grams twice weekly over 10 months) and various alternative therapies, including thymus protein extract, niacinamide, N-acetylcysteine and whole thyroid extract.

Seven months after the metastases were discovered, the woman's chest radiograph was normal, except for possible scarring in the left lung.

The authors note that the metastases were not examined for malignancy " had they been proven malignant, one could more confidently conclude that the vitamin C treatment had conferred benefit. However, the clinical symptoms and disease course of the lesions, the authors write, "make any other diagnosis unlikely." Unfortunately, upon subsequent diagnosis of small-cell lung cancer four years later, the woman "a long-time smoker" chose but did not respond to vitamin C treatment.

Second case study. This case involved a 49-year-old man with a primary bladder tumor with satellite tumors. Declining chemotherapy and radiotherapy, the patient chose to receive 30 grams of IV vitamin C twice weekly for three months, followed by 30 grams once every 1-2 months for four years, interspersed with more frequent infusions. He also used supplements, including botanical extract, chondroitin sulfate, chromium picolinate, flax oil, glucosamine sulfate, a-lipoic acid, Lactobacillus acidophilus, L. rhamnosus and selenium.

Nine years after diagnosis, the man is in good health and has had no symptoms of recurrence or metastasis.

The authors noted that this outcome is surprising, because, "when treated only locally, as in this case, invasive transitional cell bladder cancer almost invariably develops into clinically apparent local or metastatic disease within a short period.

Third case study. The third case involved a 66-year-old woman with diffuse large B-cell lymphoma confirmed by histopathologic analysis. The woman accepted a five-week course of radiation, but refused chemotherapy. Instead, she chose to receive 15 grams of IV vitamin C twice weekly for two months, 15 grams 1-2 times per week for seven months, then 15 grams every 2-3 months for about one year. She also took beta-carotene, bioflavonoids, chondroitin sulfate, coenzyme Q10, dehydroepiandrosterone, a multiple vitamin supplement, N-acetylcysteine, a botanical supplement and bismuth tablets.

During the first year after diagnosis and during treatment, on several occasions the woman had palpable lymph nodes, but after one year and for 10 years since then, she has had normal health and no sign of B-cell lymphoma.


On the significance of these three case studies, the researchers commented, "although they do not provide grounds for advocating intravenous vitamin C therapy as a cancer treatment, these cases increase the clinical plausibility of the notion that vitamin C administered intravenously might have effects on cancer under certain circumstances.

They also noted that spontaneous remission of tumors is known to occur occasionally, "although the 3 cancers reported here are dissimilar, and that these study subjects were also taking alternative medical products.

In summary, Dr Padayatty and colleagues said that the results of these case studies "increase the clinical plausibility of the notion that vitamin C administered intravenously might have effects on cancer under certain circumstances."

Re-Assessment Urged for Intravenous Vitamin C and Cancer, MedPage Today, March 27, 2006.
Sebastian J Padayatty et al. Intravenously administered vitamin C as cancer therapy: three cases, Canadian Medical Association Journal, volume 174(7), pages 937-942, March 28, 2006.

Posted: April 2006