Vitamin C, available in several foods and dietary supplements, shows some anticancer effects, including better survival among people with breast cancer.

How do experts use oral vitamin C?

Integrative experts provide recommendations for oral vitamin C in treating people with cancer. Learn more about the approaches and meanings of recommendations ›

Published protocols, programs, and approaches

These protocolsa package of therapies combining and preferably integrating various therapies and practices into a cohesive design for care, programs, and approaches by leaders in integrative cancer care use or recommend oral vitamin C.

We do not recommend specific integrative protocols or programs but provide information for you to evaluate with your healthcare team.

Lise Alschuler, ND, FABNO, and Karolyn Gazella

These books describe approaches for certain cancer types, or along with certain conventional therapy treatments, or for particular conditions such as insulin resistance.

Uses of oral vitamin C:

  • Prevent bladder cancer recurrence
  • Reduce risk of cancer:
    • Cervical cancer
    • Gastric cancer
    • Liver cancer
    • Ovarian cancer
    • Pancreatic cancer
    • Prostate cancer
    • Lung cancer 
    • Non-melanoma skin cancer
  • During lung cancer treatment
  • Hormonal balance (inflammatory triggers)
  • Reduce oxidative stress
  • Immune enhancement
  • Anti-inflammatory
  • Normalize stress hormone levels
  • Tissue healing after surgery
  • Treatment recovery program: replenishing antioxidant levels

Keith Block, MD

Block KI. Life over Cancer: The Block Center Program for Integrative Cancer Care. New York: Bantam Dell. 2009.

The integrative Block Program has recommendations to people who are at different places along the cancer continuum:

  • Those who’ve been recently diagnosed
  • Those in treatment
  • Those who’ve concluded treatment and need to remain vigilant to prevent recurrence

Uses of oral vitamin C:

  • Core diet plan
  • Antioxidant support formula
  • Immune surveillance
  • Coagulation terrain modifier
  • Hyperadapted stress pattern

Gerald M. Lemole, MD; Pallav K. Mehta, MD; and Dwight L. McKee, MD

Lemole GM, Mehta PK, McKee DL. After Cancer Care: The Definitive Self-Care Guide to Getting and Staying Well for Patients with Cancer. New York, New York: Rodale, Inc. 2015.

These doctors present easy-to-incorporate lifestyle changes to help you “turn on” hundreds of genes that fight cancer, and “turn off” the ones that encourage cancer, while recommending lifestyle approaches to address each type.

Recommend dietary intake of vitamin C as part of a whole-foods diet 

Vitamin C can block the synthesis of nitrite, which is converted into powerful carcinogens called nitrosamines.

Barbara MacDonald, ND, LAc

MacDonald B. The Breast Cancer Companion—A Complementary Care Manual: Third Edition. Self-published. 2016.

Naturopathic physician Barbara MacDonald provides information about breast cancer, its conventional treatment, and natural approaches to enhancing treatment, managing side effects, reducing risk of recurrence, and healthy living after cancer treatment is completed.

Uses of oral vitamin C:

  • Wound healing after surgery
  • Constipation from pain medications or some chemotherapy drugs
  • Liver support with liver metastasis
  • Improve immunity during treatment
  • Herpes/cold sores during treatment
  • After treatment: reduce mortality and prevent recurrence
  • As part of pre-biopsy and pre-surgical plan for immune support and wound healing: Begin 2 weeks before biopsy and continue until treatment plan is known. Begin 2 weeks before surgery. Also see a caution against using high-dose vitamin C before biopsy or surgery in Safety and precautions ›
  • During cancer treatment: 
    • Evidence shows that it increases the cytotoxic effects of adriamycin/cytoxan, paclitaxel (Taxol): increased cytotoxic effect, or fluorouracil (5-FU) 
    • Tamoxifen: help reduce negative lipid changes

Neil McKinney, BSc, ND

McKinney N. Naturopathic Oncology, Fourth Edition. Victoria, BC, Canada: Liaison Press. 2020.

This book includes descriptions and uses of many natural and complementary protocols for cancer in general and for specific cancers. It also includes information on integrative support during conventional cancer treatment.

Uses of oral vitamin C:

  • 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
  • General protocol

Gurdev Parmar, ND, FABNO, and Tina Kaczor, ND, FABNO

Parmar G, Kaczor T. Textbook of Naturopathic Oncology: A Desktop Guide of Integrative Cancer Care. 1st edition. Medicatrix Holdings Ltd. 2020.

This book provides information on the treatment of 24 cancers, plus the most effective treatments of the most common symptoms affecting cancer patients while they undergo chemotherapy, radiotherapy, or surgery.

Uses of oral vitamin C:

  • Repletion and antioxidant effect
  • Cervical cancer
  • Multiple myeloma

Nasha Winters ND, FABNO, LAc, DiplOM, and Jess Higgins Kelley, MNT

Winters ND, Kelley JH. The Metabolic Approach to Cancer. 2017. Chelsea Green Publishing.

This book’s metabolic approach to cancer is a “naturopathic nutrition program that uses the medicinal powers of traditional foods, therapeutic diets and non-toxic lifestyle approaches as cancer counteragents and preventives.” The program focuses on 10 terrain elements and how to assess them and bring them into balance.

Oral vitamin C is good for healthy immune function and adrenal gland support. The authors recommend that supplements come from quality sources, as many oral vitamin C supplements are made with genetically modified corn.

Traditional medicine

Some plants used in traditional Chinese medicine are high in vitamin C.

Learn more about traditional medicine approaches and how to find practitioners: Finding Integrative Oncologists and Other Practitioners ›

Other assessments

Bastyr University Research Institute and Fred Hutchinson Cancer Research Center

Oral vitamin C is listed among integrative oncology therapies recommended by oncology naturopaths (ND, FABNO) to breast cancer patients.1Standish LJ, Dowd F et al. Breast cancer integrative oncology care and its costs. Integrative Cancer Therapies. 2017 Mar;16(1):85-95.

Helpful link

National Institutes of Health Office of Dietary Supplements

Vitamin C ›

Keep reading about oral vitamin C


Nancy Hepp, MS

Lead Researcher
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS Lead Researcher

Laura Pole, MSN, RN, OCNS

Senior Clinical Consultant
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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, MSN, RN, OCNS Senior Clinical Consultant


Jen Green, ND, FABNO

Naturopathic oncologist and CancerChoices advisor
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Dr. Green is a naturopathic physician who is board-certified in naturopathic oncology (FABNO). Dr. Green is also a cofounder/research director for Knowledge in Integrative Oncology Website, a nonprofit website that harvests up-to-date research in integrative oncology to support evidence-informed decision making. Dr. Green has published scientific articles in journals such as the American Urology Association Update SeriesJournal of Alternative & Complementary Medicine and Natural Medicine Journal.

Jen Green, ND, FABNO Naturopathic oncologist and CancerChoices advisor

Last update: May 7, 2024

Last full literature review: January 2023

CancerChoices provides information about integrativein cancer care, a patient-centered approach combining the best of conventional care, self care, and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocialtherapy, and acupuncture therapies and self carelifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.

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