Vitamin D is a hormone created by the body when skin is exposed to ultraviolet rays in sunlight. It is found naturally in a small number of foods and can also be taken as a fat-soluble dietary supplement.

How do experts use vitamin D?

Both medical groups and integrative experts provide recommendations for vitamin D in treating people with cancer. Learn more about the approaches and meanings of recommendations: Integrative Oncology Programs and Expert Guidelines ›

Clinical practice guidelines

More guidelines, specific to medical professionals, are in Are you a health professional?

This 2011 guideline suggests defining vitamin D deficiency as 25(OH)D levels below 20 ng/mL, insufficiency as 25(OH)D of 21–29 ng/mL, and sufficiency starting at 30 ng/mL.

These guidelines suggest that all adults who are vitamin D deficient be treated with 50,000 IU of vitamin D2 or vitamin D3 once a week for 8 weeks or its equivalent of 6000 IU of vitamin D2 or vitamin D3 per day to achieve a blood level of 25(OH)D above 30 ng/ml, followed by maintenance therapy of 1500–2000 IU per day.

Society for Integrative Oncology

Clinical practice guidelines on the evidence-based use of integrative therapies during and after breast cancer treatment ›

This set of guidelines has been endorsed by the American Society of Clinical Oncology (ASCO).1Lyman GH, Greenlee H et al. Integrative therapies during and after breast cancer treatment: ASCO endorsement of the SIO clinical practice guideline. Journal of Clinical Oncology. 2018 Sep 1;36(25):2647-2655.

The 2017 guidelines regarding breast cancer patients evaluates vitamin D2 as having insufficient evidence to recommend using for pain.

Researchers from these organizations found insufficient evidence to recommend vitamin D to treat aromatase inhibitor-related joint pain.

Published protocols, programs, and approaches

Vitamin D is used in programs, approaches, and protocolsa package of therapies combining and preferably integrating various therapies and practices into a cohesive design for care from these integrative oncologists, drawing from both scientific research and observations from years or even decades of treating people with cancer.

Lise Alschuler, ND, FABNO, and Karolyn Gazella

Approaches are described for certain cancer types, or along with certain conventional therapy treatments, or for particular conditions such as insulin resistance.

Uses of vitamin D:

  • Breast cancer
  • Colon cancer
  • Kidney cancer
  • Lung cancer
  • Melanoma
  • Ovarian cancer
  • Prostate cancer
  • Blood sugar support

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 vitamin D:

  • Core diet plan: vitamin supplementation
  • Symptom management: osteoporosis
  • Blood sugar support and terrain modification
  • Progression pathway targeting
  • Remission maintenance program: chemoprevention

Dr. Block says that off-label use of calcitriol, which is the most active form of vitamin D, is of particular interest in prostate cancer. Preclinical evidence shows clear benefit and early clinical evidence to date is promising but not yet conclusive.2Ben-Eltriki M, Deb S, Guns ES. Calcitriol in combination therapy for prostate cancer: pharmacokinetic and pharmacodynamic interactions. Journal of Cancer. 2016 Jan 15;7(4):391-407.

Dr. Block cautions against giving alpha-tocopherol alone, as this may deplete the body of other important components of vitamin E.

Raymond Chang, MD, FACP

Chang R. Beyond the Magic Bullet: The Anti-Cancer Cocktail. New York: Square One Publishers. 2012.

This book describes a “new therapy based on the knowledge that certain off-label drugs, nutrients, and therapies are each somewhat effective against cancer.” Dr. Chang combines approaches for added benefit.


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.

Uses of vitamin D:

  • Bladder cancer
  • Breast cancer
  • Colorectal cancer
  • Endometrial cancer
  • Leukemia
  • Lung cancer
  • Lymphoma
  • Melanoma
  • Prostate cancer
  • Renal cancer
  • Thyroid cancer

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.

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 vitamin D:

  • General cancer
  • Breast cancer
  • Leukemia and myelodysplastic syndrome
  • Lung cancer
  • Lymphoma
  • Melanoma
  • Multiple myeloma
  • Pancreatic cancer
  • Prostate cancer
  • Sarcoma
  • Skin cancer
  • Bastyr University Integrative Oncology Research Center protocol for stage IV breast cancer3McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016. p. 316.

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 vitamin D:

  • Chemotherapy Induced Peripheral Neuropathy (CIPN)
  • Breast cancer
  • Colon cancer
  • Head and neck cancer
  • Hodgkin lymphoma
  • Melanoma
  • Myeloma
  • Ovarian cancer
  • Prostate cancer
  • Thyroid cancer

David Servan-Schreiber, MD, PhD

Servan-Schreiber D. Anticancer: A New Way of Life. New York: Penguin Books. 2009.

This book provides tips on how people living with cancer can fight it and how healthy people can prevent it.


Other expert assessments

Donald Abrams, MD, and Andrew Weil, MD

Doctors Abrams and Weil state that vitamin D supplementation along with calcium is recommended for people undergoing treatment that can cause bone loss—such as aromatase inhibitors or surgical oophorectomy—or who have ovarian failure.

Current Oncology Reports

An expert review of evidence suggests that vitamin D “might have a potential role in alleviating cancer-related fatigue” among people with a deficiency.4David A, Hausner D, Frenkel M. Cancer-related fatigue-is there a role for complementary and integrative medicine? Current Oncology Reports. 2021 Nov 7;23(12):145. 

Survey of naturopathic physicians

A 2018 survey identified vitamin D as one of the most frequently identified interventions used by members of the Oncology Association of Naturopathic Physicians for lung and gastroesophageal cancer care.5Seely D, Ennis JK, McDonell E, Zhao L. Naturopathic oncology care for thoracic cancers: a practice survey. Integrative Cancer Therapies. 2018 Sep;17(3):793-805.


Sun exposure

You make vitamin D when your skin is exposed to relatively intense sunlight. People with light skin can produce sufficient vitamin D with less than 15 minutes of exposure to the sun around noon on a summer day. The time needed increases among people with darker skin, up to two hours for people with very dark skin.

The farther the sun is from directly overhead, the less efficiently you’ll produce vitamin D. A rule of thumb is that you produce vitamin D only if your shadow is shorter than you are.6Vitamin D and Cancer with William B. Grant, PhD. Moss Report Podcast. June 22, 2022. Viewed September 12, 2022. People who live far from the equator may not make any vitamin D in the winter, even at noon.7Raman R. How to safely get vitamin D from sunlight. Healthline. April 28, 2018. Viewed September 12, 2022.


The National Academies Health and Medicine Division (formerly the Institute of Medicine) recommends a daily dietary allowance of vitamin D of 600 IU/day (increasing to 800 IU/day at age 71) with the upper level intake at 4,000 IU/day starting at age nine for healthy individuals.8Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D (chapter 7). 2011. Viewed November 2, 2021. Higher doses may be needed among people treated with steroids.9Albert Einstein College of Medicine. Oral steroids linked to severe vitamin D deficiency in nationwide US study. ScienceDaily. September 30, 2011. Viewed March 6, 2019.

Vitamin D measurements: 40 IU=1 microgram

Dosage has not been standardized for use in cancer care, but recommendations are available from these sources:

Natural Medicines Database ›

Subscription required

Beer TM, Hough KM et al. Weekly high dose calcitriol and docetaxel in advanced prostate cancer. Seminars in Oncology. 2001;28(4 Suppl 15):49–55.

Also see published programs and approaches (above).

General information about dosing

Find general dosing guidelines regarding natural products and supplements.

Expert commentary

Dosing vitamin D supplements

In his Grand Rounds Urology lecture, Aaron Katz, MD, cites the literature supporting vitamin D’s positive effect in reducing disease risk, including prostate cancer. Dr. Katz’s practice is to “obtain [baseline] vitamin D levels on all of my [prostate cancer] patients that are on active surveillance, whether it be in the recurrent cases or in primary [cases]. Then. . . restore about 1,000 international units (IUs) of vitamin D, [to] give you just a bump [in blood levels] up of around 10 ng/mL. Most people in the field believe that the therapeutic range is somewhere between 40 and 50 ng/mL. ”10Katz A. Diet and Supplements for Men with Rising PSA. Grand Rounds Urology. January 2015. Viewed September 20, 2018.

CancerChoices Senior Clinical Consultant Laura Pole, RN, MSN, OCNS: In dosing vitamin D to bring up to therapeutic levels, keep in mind that many clinicians, including CancerChoices advisor Donald Abrams, MD, feel that doses greater than 4000 IU daily lead to increased risk of calcification of blood vessels. Dr. Katz reports that he has not seen any problems dosing with 5000 IU vitamin D per day for 3 months, then re-checking the vitamin D level. We advise not to take high doses of vitamin D without medical advice and supervision.

Take vitamin D with healthy fats

Kelly Burch and Allison Herries, RDN, from VeryWell Health: “Vitamin D is a fat-soluble vitamin, which means the body processes them in a similar way that it processes fat. Because of that, it’s best to take vitamin D with a meal that contains some healthy fats.”11Burch K. Magnesium and vitamin D: benefits, dosage, and why to consider taking both. VeryWell Health. December 14, 2023. Viewed December 18, 2023.

Can you wash vitamin D from your skin?

A claim has circulated widely that vitamin D produced in your skin is subject to removal if you wash with soap after sun exposure. Experts say this is not likely: “After exposure to sunlight vitamin D3 remains in the skin even when the skin is washed with soap and water immediately after the exposure to sunlight.”12Wacker M, Holick MF. Sunlight and vitamin D: a global perspective for health. Dermatoendocrinology. 2013 Jan 1;5(1):51-108.

Dr. James Spurgeon discusses how vitamin D is produced in your skin and not able to be washed off after sun exposure.

Play video

Helpful links

Keep reading about vitamin D


Nancy Hepp, MS

Lead Researcher
View profile

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

Dr. Ryan served as a research associate for CancerChoices. She is a licensed and board certified naturopathic physician and acupuncturist in Oregon. Dr. Ryan is the founder of Gentle Natural Wellness, a clinic specializing in bridging classical Chinese medicine with naturopathic medicine to provide individualized, compassionate care for people in the community. A Doctorate of Naturopathic Medicine and Master of Science in Oriental Medicine with honors from the National University of Natural Medicine, research in medical anthropology at the University of Hawai’i and George Mason University, language and culture programs at Obirin University (Tokyo) and Sogang University (Seoul), and studies of Chinese herbal medicine and qigong in China have provided a diverse background that has helped form a foundation for her community health and healing path.

Emily Ryan, ND, MSOM, LAc Research Associate


Laura Pole, MSN, RN, OCNS

Senior Clinical Consultant
View profile

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

Last update: April 6, 2024

Last full literature review: February 2022

CancerChoices provides information about integrative in 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 psychosocial therapy, and acupuncture therapies and self-care lifestyle 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.

Learn more