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.

Affordability and access

Prescription required?

  • Not for over-the-counter supplements, but we recommend you consult your oncology team if you are taking or planning on taking vitamin D supplements
  • Some formulations and analogs of vitamin D require a prescription

Forms of vitamin D

Vitamin D supplements come in two forms, D2 and D3. Vitamin D3 (cholecalciferol) is found mainly in animals, while vitamin D2 comes from plant-sourced foods. Vitamin D2 must be converted to D3 by your body. Small amounts of vitamin D3 and D4 are also found in mushrooms.1Cardwell G, Bornman JF, James AP, Black LJ. A review of mushrooms as a potential source of dietary vitamin D. Nutrients. 2018 Oct 13;10(10):1498. Since vitamin D2 is cheaper to produce, it’s the most common form in fortified foods, but it’s also less effective at raising your blood serum levels.2Vitamin D2 vs. D3: What’s the Difference? Healthline. February 21, 2020. Viewed July 1, 2022. When shopping for supplements, pay attention to whether you’re buying vitamin D2 or D3, consistent with whether you want nutrients sourced from animals, how severe your deficiency may be, and what your doctor recommends.

The body converts vitamin D, first in the liver to 25-hydroxyvitamin D or simply 25(OH)D, also known as calcidiol. Then it is converted again, primarily in the kidneys, forming the physiologically active hormone 1,25-dihydroxyvitamin D or 1,25(OH)2D, also known as calcitriol.3Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals. National Institutes of Health. June 2, 2022. Viewed June 8, 2022; Vitamin D. Council. What is vitamin D? Viewed June 8, 2022.

You may find vitamin D under these alternate names and brands: 

Vitamin D2

  • Drisdol
  • Ergocalciferol

Vitamin D3 

  • Cholecalciferol
  • Delta D3

Prescription vitamin D

Prescription-only and other forms of vitamin D usually used to treat specific medical conditions other than cancer include these: 

  • DHT or dihydrotachysterol
  • DHT Intensol
  • One-Alpha® or alfacalcidol 
  • Rocaltrol or calcitriol 
  • Hectorol
  • Rayaldee
  • Zemplar

Where to access

Vitamin D is available in some foods:

  • Egg yolks
  • Cod liver oil
  • Fish oil
  • Wild fish such as salmon, sardines, herring, and cod
  • Blood sausage
  • Some organ meats, such as liver
  • Butter
  • Mushrooms, including medicinal mushrooms, that have been exposed to sunlight, but as a source of vitamin D2;4Keegan RJ, Lu Z, Bogusz JM, Williams JE, Holick MF. Photobiology of vitamin D in mushrooms and its bioavailability in humans. Dermatoendocrinology. 2013 Jan 1;5(1):165-76; Plotnikoff GA. Anticancer medicinal mushrooms can provide significant vitamin D2 (ergocalciferol). International Journal of Medicinal Mushrooms. 2005;7(3):471-2. vitamin D2 is less effective than vitamin D3, which comes only from animal sources, as noted above
  • Some dairy products, orange juice, soy milk, and cereals to which vitamin D has been added5Derrer DT. Top foods for calcium and vitamin D. WebMD. July 22, 2020. Viewed June 8, 2022.

Vitamin D supplements are available without a prescription in retail stores:

  • Drug stores
  • Supplement stores
  • Online supplement distributors

As noted above, vitamin D2 is less effective than vitamin D3, which comes only from animal sources.


  • Supplements are generally inexpensive (less than $500 US/year) 

Helpful links

A place to buy brands that have been evaluated for quality

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Keep reading about vitamin D


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

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
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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

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.

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