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Intravenously administered vitamin C
as cancer therapy: three cases
Sebastian J. Padayatty,
Hugh D. Riordan, Stephen M. Hewitt, Arie
Katz, L. John Hoffer and Mark Levine
From the Molecular and
Clinical Nutrition Section, Digestive Diseases Branch, National
Institute of Diabetes and Digestive and Kidney Diseases (Padayatty,
Katz, Levine), and the Laboratory of Pathology, Centers for Cancer
Research, National Cancer Institute (Hewitt), National Institutes of
Health, Bethesda, Md.; Lady Davis Institute for Medical Research (Hoffer),
McGill University, Montréal, Que.; Bio-Communications Research
Institute (Riordan) (deceased), Wichita, Kan.
Correspondence to: Dr. Mark Levine, Molecular and Clinical
Nutrition Section, Bldg. 10, Rm 4D52–MSC 1372, National Institutes
of Health, Bethesda MD 20892–1372; MarkL@mail.nih.gov.
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Early clinical studies showed that
high-dose vitamin C, given by intravenous and oral routes,
may improve symptoms and prolong life in patients with
terminal cancer.
Double-blind placebo-controlled studies of oral vitamin C
therapy showed no benefit.
Recent evidence shows that oral administration of the
maximum tolerated dose of vitamin C (18 g/d) produces peak
plasma concentrations of only 220 µmol/L, whereas
intravenous administration of the same dose produces plasma
concentrations about 25-fold higher.
Larger doses (50–100 g) given intravenously may result in
plasma concentrations of about 14 000 µmol/L.
At concentrations above 1000 µmol/L, vitamin C is toxic to
some cancer cells but not to normal cells in vitro.
We found 3 well-documented cases of advanced cancers,
confirmed by histopathologic review, where patients had
unexpectedly long survival times after receiving high-dose
intravenous vitamin C therapy.
We examined clinical details of each case in accordance
with National Cancer Institute (NCI) Best Case Series
guidelines.
Tumour pathology was verified by pathologists at the NCI
who were unaware of diagnosis or treatment.
In light of recent clinical pharmacokinetic findings and in
vitro evidence of anti-tumour mechanisms, these case
reports indicate that the role of high-dose intravenous vitamin
C therapy in cancer treatment should be reassessed.
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