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We’re busy updating our review of vitamin C and will provide a rating when that’s complete. While we’re working, we share a summary from our predecessor website, Beyond Conventional Cancer Therapies. The information we share here was last updated in February 2021.

Please consider supporting our update and revision to this information.

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Vitamin C

CancerChoices plans to write a summary on vitamin C. While our summary is in development, you can visit these sites:

Before using this therapy, consult your oncology team about interactions with other treatments and therapies. Also make sure this therapy is safe for use with any other medical conditions you may have.

Cautions

A review found intravenous vitamin C use generally safe, except in patients with renal impairment or glucose 6 phosphate dehydrogenase deficiency.1 Although at least one case study reported a kidney stone occurrence during IV vitamin C treatment,2 prospective studies found no association between a high daily intake of vitamin C and the risk of stone formation, even when consumed in large doses, in both men and women3

The About Herbs and CAM-Cancer summaries of vitamin C and the The Centre for Health Innovation’s monograph list several contraindications, adverse reactions, herb-drug interactions and herb-lab interactions. For instance, in some studies, vitamin C was found to reduce the effectiveness of some chemotherapy drugs. Serious harm can occur using high-dose vitamin C in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency, an inborn metabolism error. Read the summaries for more information:

TRC Natural Medicines Database provides an even more extensive listing and discussion of adverse reactions, contraindications, and herb-drug interactions: TRC Natural Medicines: Vitamin C (subscription required)

Neil McKinney, ND, lists a number of cautions and contraindications not listed in other sources, such as avoiding megadoses of vitamin C in leukemia, as it can paradoxically increase malignant cell proliferation. He also cautions not to use during the same week as Artemisinin therapy, nor in tumors with high risk of tumor lysis syndrome and hemorrhage.4

Patients on regular dialysis treatment may be at increased risk for oxalate supersaturation in IV vitamin C use.5

CancerChoices strongly advises that you speak with your oncology physician if you are thinking about or are taking high-dose vitamin C. CancerChoices also strongly advises that if you use high dose vitamin C, you seek care from a healthcare professional knowledgeable and experienced in administering this treatment to people with cancer.

Highlighted Video

Integrative oncologist and BCCT advisor Brian Bouch, MD, briefly discusses antioxidants and high-dose vitamin C (IV).

Dosing

CancerChoices does not recommend therapies or doses, but only provides information for patients and providers to consider as part of a complete treatment plan. Patients should discuss therapies with their physicians, as contraindications, interactions and side effects must be evaluated.

Dosage recommendations are available from these sources:

  • Alschuler LN, Gazella KA. The Definitive Guide to Cancer, 3rd Edition: An Integrative Approach to Prevention, Treatment, and Healing. Berkeley, California: Celestial Arts. 2010.
  • Block KI. Life over Cancer: The Block Center Program for Integrative Cancer Care. New York: Bantam Dell. 2009.
  • McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016.
  • Moss Reports (purchase required): Select from the list of cancers down the left side of the page for a report describing uses of conventional, complementary, alternative and integrative therapies related to that cancer. Ralph Moss is among the most knowledgeable and balanced researchers of integrative cancer therapies. The cost of his Moss Reports is not negligible, but many patients find them of considerable value. Moss is also available for consultations.
  • TRC Natural Medicines: Vitamin C (subscription required)

Integrative Programs, Protocols and Medical Systems

  • Programs and protocols
    • Alschuler & Gazella complementary approaches6
      • Bladder cancer
      • Cervical cancer
      • Gastric cancer
      • Liver cancer
      • Pancreatic cancer
      • Hormonal balance (inflammatory triggers)
      • Immune enhancement
      • Anti-inflammatory
      • Stress reduction
      • Post-operative healing program
      • Treatment recovery program
  • Bastyr University Integrative Oncology Research Center protocol for stage 4 breast cancer7
  • Block program8
    • Core diet plan
    • Antioxidant support formula
    • Immune surveillance
    • Coagulation terrain modifier
    • Hyperadapted stress pattern
  • Lemole, Mehta & McKee protocols: whole foods diet9
  • McKinney protocols
    • Bladder cancer
    • Brain cancer
    • Breast cancer
    • Cervical cancer
    • Gallbladder cancer
    • Head and neck cancer
    • Lung cancer
    • Lymphoma
    • Multiple myeloma
    • Myelodysplastic syndrome
    • Pancreatic cancer
    • Prostate cancer
    • Renal cell cancer
    • Stomach cancer
    • Uterine cancer
    • Bone metastasis
    • Stem cell modulation
    • Natural compound to target cancer growth factors
    • Oral form: general protocol
    • IV form: foundation protocol for naturopathic oncology to support chemotherapy, improve quality of life and cancer cell cytotoxicity
  • Traditional systems
    • Traditional Chinese medicine: some plants used in TCM are high in vitamin C

Resources

References

  1. Padayatty SJ, Sun AY et al. Vitamin C: intravenous use by complementary and alternative medicine practitioners and adverse effects. PLoS One. 2010 Jul 7;5(7):e11414.
  2. Riordan HD et al. Intravenously administered vitamin C as cancer therapy: three cases. CMAJ: Canadian Medical Association Journal. 2006 Mar 28;174(7):937-42.
  3. Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men. Journal of Urology. 1996 Jun;155(6):1847-51; Curhan GC, Willett WC, Speizer FE, Stampfer MJ. Intake of vitamins B6 and C and the risk of kidney stones in women. Journal of the American Society of Nephrology. 1999 Apr;10(4):840-5.
  4. McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016. 
  5. Canavese C, Petrarulo M et al. Long-term, low-dose, intravenous vitamin C leads to plasma calcium oxalate supersaturation in hemodialysis patients. American Journal of Kidney Diseases. 2005 Mar;45(3):540-9.
  6. Alschuler LN, Gazella KA. The Definitive Guide to Cancer, 3rd Edition: An Integrative Approach to Prevention, Treatment, and Healing. Berkeley, California: Celestial Arts. 2010; Alschuler LN, Gazella KA. The Definitive Guide to Thriving after Cancer: A Five-Step Integrative Plan to Reduce the Risk of Recurrence and Build Lifelong Health. Berkeley, California: Ten Speed Press. 2013.
  7. McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016. p. 316.
  8. Block KI. Life over Cancer: The Block Center Program for Integrative Cancer Treatment. New York: Bantam Dell. 2009.
  9. Lemole G, Mehta P, McKee D. After Cancer Care: The Definitive Self-Care Guide to Getting and Staying Well for Patients with Cancer. New York, New York: Rodale, Inc. 2015.
  10. McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016.