Vitamin C Infusion for Cancer

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Vitamin C Infusion for Cancer

Vitamin C Infusion for Cancer

What is Vitamin C Infusion?

An infusion refers to an IV infusion. IV is short for intravenous meaning that the contents drip into the vein (intra-venous). Chances are you have had an IV infusion at some point in your life.

Most times the liquid dripping into you was either saline (salt water, also called “normal saline”) or 5% dextrose (also called D5W) and these can also be mixed with medication. This post will cover the evidence for a high dose vitamin C IV which is used by many complimentary or alternative health practitioners as a treatment for cancer outside of the conventional medical system.

You can use this Table of Contents to help you navigate the information in this post


An IV bag is hanging and chamber shows half full of vitamin C infusion
An infusion of vitamin C from an IV drip into the vein is required to reach the blood level targets that can’t be achieved with food.

History of IV Vitamin C for Cancer

The use of vitamin C infusion as a cancer therapy is controversial. IV vitamin C was first developed as a therapeutic agent for cancer in the 1970s (1). Initial studies suggested improved survival times for those treated with supplemental vitamin C which then sparked wider interest in its use (2, 3).

IV vitamin C has long been used in the field of Complementary and Alternative Medicine (CAM) as part of cancer treatment. Surveys of practitioners attending CAM conferences in the United States in 2006 and 2008 found that 172 (86% of respondents) had administered IV vitamin C to patients, including 2,888 cancer patients, during that time (4).

Although the extent of IV vitamin C use in Canada is unknown, it is currently being offered in integrative health clinics throughout the country (56, 7).

Based on Canadian Cancer Society discussion forums, it appears there is public interest in IV vitamin C treatments (8). As IV vitamin C may be currently used or may be a treatment of interest to cancer patients, it is important for dietitians [and the public] to understand the current evidence surrounding its use and effectiveness.

Linus Pauling
Linus Pauling, an American chemist and British cancer surgeon Ewan Cameron, published the first paper on vitamin C infusion for cancer treatment in 1974.

How does Vitamin C Infusion Work? 

When vitamin C is taken orally (from food or supplements), blood levels of the vitamin are tightly controlled (<0.30 mmol/L), whereas high blood levels are achievable with IV vitamin C administration (up to 20 mmol/L) (9, 10).

In vitro (experimental studies in petri dishes), high dose vitamin C has been shown to kill cancer cells but not normal cells (11, 12).  In animal studies, high-dose vitamin C infusion was found to prevent the growth of transplanted aggressive cancers (13, 14, 15, 16).

A few processes have been proposed for the potential anti-cancer effects of vitamin C infusion. The most widely accepted process is based on high dose vitamin C acting as a pro-oxidant, and leading to the formation of hydrogen peroxide which causes damage to cancer cells (11, 12, 17, 18).

Glass of fresh squeezed lemon and orange juice with an orange and lemon beside it
Vitamin C makes us think of citrus fruit. But consuming vitamin C rich foods cannot provide the same blood level of vitamin C that an infusion can.

Does Vitamin C Infusion have Anti-tumor Effects in Humans?

Two systematic reviews have explored the potential anti-tumor effects of IV vitamin C in cancer patients as a stand alone therapy or with other treatment, such as chemotherapy or radiation therapy (19, 20).

Review by Fritz and Colleagues (2014)


  • 1 randomized controlled trial
  • 7 uncontrolled trials
  • 6 observational studies
  • 14 case reports

In all of these, a high-dose of IV vitamin C of 5 grams or more was administered (19).

The randomized controlled trial showed that IV vitamin C in combination with standard chemotherapy trended toward longer time to relapse and improved survival compared to standard chemotherapy alone (21).

Based on preliminary findings, the authors report IV vitamin C in addition to chemotherapy may have potential to improve tumor response (22) and patient survival time (23).

Review by Jacobs and Colleagues (2015)


  • 1 randomized controlled trial
  • 8 non-randomized phase I or II trials
  • 1 cohort study
  • 6 case reports (20)

They found no consistent evidence for anti-tumor effects or improved survival outcomes with IV vitamin C administration in a controlled setting (20).

The authors report that the trials were generally small, included a variety of cancer types, most were non-randomized (participants got to choose whether to receive IV vitamin C or not), lacked a control group, and often used IV vitamin C in combination with another agent (20).

Bottom Line for IV Vitamin C and Anti-Tumor Effects

In order to determine if vitamin C infusion has antitumor effects in humans, there is a need for more rigorous evidence with larger trials using randomization and blinding in study design (19, 20).


Does IV Vitamin C Improve the Quality of Life in Cancer Patients?

In the systematic reviews by Jacobs and others (2015) and Fritz and others (2014), these groups explored the effects of IV vitamin C on quality of life (19, 20). All together they found, there is weak evidence that IV vitamin C may improve cancer-related quality of life and symptom severity, or reduce the toxicity of chemotherapy.

Non-randomized studies assessing oral and vitamin C infusion on cancer and chemotherapy-related quality of life using validated questionnaires found patients reported decreases in common symptoms such as fatigue, pain, nausea/vomiting, insomnia, and appetite loss, following administration of IV vitamin C (24, 25).

They also found improvements in reported overall health, and enhanced physical, emotional, cognitive, and social functioning. In contrast, another clinical trial found no significant benefit of IV vitamin C to quality of life (10).

One retrospective cohort study found that breast cancer patients treated with IV vitamin C in addition to standard therapy had a statistically and clinically significant reduction in chemotherapy-related side effects compared to patients treated with standard therapy alone (26).

As well, a randomized trial of ovarian cancer patients found reductions in chemotherapy-related toxicities (21).

Bottom Line for IV Vitamin C and Quality of Life

Due to a lack of double blind, placebo-controlled trials, it is unclear how much of quality of life scores are related to the effects of the cancer, the chemotherapy, the IV vitamin C, or other types of supportive care (20).

The way quality of life was reported, the IV vitamin C dose and frequency, and the length of IV vitamin C administration varied in these studies. As well, a possible placebo effect cannot be ruled out (20). This is why the evidence for IV vitamin C improving cancer-related quality of life is weak.

Is a Vitamin C Infusion Safe?

Evidence from systematic reviews has found IV vitamin C therapy to be mostly well-tolerated and safe (19, 20). Recent reviews report that vitamin C infusion has demonstrated a good safety profile, however screening for glucose-6-phosphate dehydrogenase deficiency, iron and copper storage diseases, impaired renal function, history of kidney stones or oxaluria, and pregnancy/lactation is recommended (27, 28).

Some negative effects reported in clinical trials that may be related to vitamin C infusion include; nausea (23, 29), diarrhea, and thirst/dry mouth (23). As well, health care providers must be careful to prevent any potential interaction between excess circulating vitamin C and the patient’s chemotherapy (27).

Summary of Vitamin C Infusion for Cancer

Although the existing research suggests that IV vitamin C may be a safe added therapy in the treatment of cancer and chemotherapy-related quality of life, these findings must be interpreted with caution as there is limited high-quality clinical evidence on its safety and effectiveness (19, 20).

There is a lack of randomized controlled trials, and the methods used in the studies published so far are different from each other which makes it difficult to make a recommendation. Until high-quality, placebo-controlled trials are completed, the use of IV vitamin C as a cancer therapy cannot be recommended, and you need to be aware of the lack of data supporting its use (20).

Additional Resources:

1. PDQ® Integrative, Alternative, and Complementary Therapies Editorial Board. PDQ High-Dose Vitamin C.
Bethesda, MD: National Cancer Institute. Updated <12/13/2017>. Accessed <04/03/2019>. [PMID: 26389504].

2. Memorial Sloan Kettering Cancer Center. c2019. Vitamin C. Updated <08/03/2018>

More on Cancer and Diet

If you enjoyed this Cancer Bites Diet Blog post, you may enjoy reading these blog posts;


References for Vitamin C Infusion for Cancer

1. Cameron E, Campbell A. The orthomolecular treatment of cancer. II. Clinical trial of high-dose ascorbic acid supplements in advanced human cancer. Chem Biol Interact. 1974;9:285-315.

2. Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: prolongation of survival times in terminal human cancer. Proc Natl Acad Sci. 1976;73:3685-3689.

3. Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: Reevaluation of prolongation of survival times in terminal human cancer. Proc Natl Acad Sci. 1978;75:4538-4542.

4. Padayatty SJ, Sun AY, Chen Q, et al. Vitamin C: intravenous use by complementary and alternative medicine practitioners and adverse effects. PLoS One. 2010;5(7): e11414.

5. [Internet]. Ottawa Integrative Cancer Centre. c2019 [cited 2019 Jun 20]. Improving Quality of Life; [about 3 screens]. Available from:

6. [Internet]. Marsden Centre for Excellence in Integrative Medicine. c2019 [cited 2019 Jun 20]. Integrative Cancer Care; [about 4 screens]. Available from:

7. [Internet]. Clear Health Inn. c2019 [cited 2019 Jun 20]. Supplementary Cancer Methods; [about 3 screens]. Available from:

8. [Internet]. Canadian Cancer Society; c2019 [cited 2019 Mar 8]. Vitamin C Intravenous in Canada; [about 8 screens]. Available from:

9. Padayatty SJ, Sun H, Wang Y, et al. Vitamin C pharmacokinetics: implications for oral and intravenous use. Ann Intern Med. 2004;140(7): 533-7.

10. Hoffer LJ, Levine M, Assouline S, et al. Phase I clinical trial of i.v. ascorbic acid in advanced malignancy. Ann Oncol. 2008;19(11):1969-74.

11. Chen Q, Espey MG, Krishna MC, et al. Pharmacologic ascorbic acid concentrations selectively kill cancer cells: action as a pro-drug to deliver hydrogen peroxide to tissues. Proc Natl Acad Sci. 2005;102(38):13604-9.

12. Chen Q, Espey MG, Sun AY, et al. Pharmacologic doses of ascorbate act as a prooxidant and decrease growth of aggressive tumor xenografts in mice. Proc Natl Acad Sci. 2008;105(32): 11105-9.

13. Verrax J, Calderon PB. Pharmacologic concentrations of ascorbate are achieved by parenteral administration and exhibit antitumoral effects. Free Radic Biol Med. 2009;47(1):32-40.

14. Du J, Martin SM, Levine M, et al. Mechanisms of ascorbate-induced cytotoxicity in pancreatic cancer. Clin Cancer Res. 2010;16(2):509-20.

15. Pollard HB, Levine MA, Eidelman O, et al. Pharmacological ascorbic acid suppresses syngeneic tumor growth and metastases in hormone-refractory prostate cancer. In Vivo 2010;24 (3):249-55.

16. Takemura Y, Satoh M, Satoh K, et al. High dose of ascorbic acid induces cell death in mesothelioma cells. Biochem Biophys Res Commun. 2010;394(2):249-53.

17. Chen Q, Espey MG, Sun AY, Lee JH, Krishna MC, Shacter E, et al. Ascorbate in pharmacologic concentrations selectively generates ascorbate radical and hydrogen peroxide in extracellular fluid in vivo. Proc Natl Acad Sci. 2007;104(21):8749-8754.

18. Parrow NL, Leshin JA, and Levine M. Parenteral ascorbate as a cancer therapeutic: a reassessment based on pharmacokinetics. Antioxid Redox Signal. 2013;19:2141-2156. doi: 10.1089/ars.2013.5372.

19. Fritz H, Flower G, Weeks L, Cooley K, Callachan M, McGowan J et al. Intravenous vitamin C and cancer: a systematic review. Integrative Cancer Therapies. 2014;3(4):280–300.

20. Jacobs C, Hutton B, Ng T, Shorr R, Clemons M. Is there a role for oral or intravenous ascorbate (vitamin C) in treating patients with cancer? A systematic review. The Oncologist. 2015;20:210–223.

21. Ma Y, Chapman J, Levine M, Polireddy K, Drisko J, Chen Q. High-dose parenteral ascorbate enhanced chemosensitivity of ovarian cancer and reduced toxicity of chemotherapy. Sci Transl Med. 2014;6:222ra218.

22. Monti DA, Mitchell E, Bazzan AJ, et al. Phase I evaluation of intravenous ascorbic acid in combination with gemcitabine and erlotinib in patients with metastatic pancreatic cancer. PLoS One. 2012;7:e29794.

23. Welsh JL, Wagner BA, van’t Erve TJ, et al. Pharmacological ascorbate with gemcitabine for the control of metastatic and node-positive pancreatic cancer (PACMAN): results from a phase I clinical trial. Cancer Chemother Pharmacol. 2013;71:765-775.

24. Yeom CH, Jung GC, Song KJ: Changes of terminal cancer patients’ health-related quality of life after high dose vitamin C administration. J Korean Med Sci. 2007;22(1):7-11.

25. Takahashi H, Mizuno H, Yanagisawa A. High-dose intravenous vitamin C improves quality of life in cancer patients. Personalized Medicine Universe. 2012;1(1):49-53.

26. Vollbracht C, Schneider B, Leendert V, Weiss G, Auerbach L, Beuth J. Intravenous vitamin C administration improves quality of life in breast cancer patients during chemo-/radiotherapy and aftercare: results of a retrospective, multicentre, epidemiological cohort study in Germany. In Vivo. 2011;25:983-990.

27. Klimant E, Wright H, Rubin D, Seely D, Markman M. Intravenous vitamin C in the supportive care of cancer patients: a review and rational approach. Curr Oncol. 2018;25(2):139-148.

28. Carr AC and Cook J. Intravenous vitamin C for cancer therapy – identifying the current gaps in our knowledge. Front Physiol. 2018;9:1182. doi: 10.3389/fphys.2018.01182.

29. Stephenson CM, Levin RD, Spector T, Lis CG. Phase I clinical trial to evaluate the safety, tolerability, and pharmacokinetics of high-dose intravenous ascorbic acid in patients with advanced cancer. Cancer Chemother. Pharmacol. 2013;72(1):139-146.


This blog was originally posted to the Oncology Network of Dietitians of Canada on August 2019 and has been republished with permission from the author and the network. Some edits were made to make the post suitable for a general audience, but did not change the opinion of its original author.