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The Power of Vitamin D in Cancer Prevention and Treatment

Well-known in both the medical community and the average household for its important role in bone health, vitamin D has been long regarded for its benefits. However, recent studies suggest there is also a strong link between vitamin D deficiency and the development of several cancer types. Furthermore, evidence shows that pre-diagnosed patients can actually reduce their risk of metastasis by ensuring adequate levels of vitamin D. So, what exactly is vitamin D and how does it work in the context of cancer? Let’s take a deeper look to explore how you can utilize vitamin D in your cancer prevention and treatment strategy. 

What is Vitamin D?

Vitamin D is the natural byproduct of a chemical interaction between energy from the sun and cholesterol in your skin. However, as humans have transitioned from living and working predominantly outside to spending more time in indoor facilities, exposure to sunlight has become increasingly limited — and in turn, has resulted in lower vitamin D levels in the overall population. In fact, current studies estimate that approximately 1 billion people worldwide suffer from vitamin D deficiency. 

Additionally, a range of factors such as age, medications, sunscreen use, geographical location, and even skin color can affect the body’s ability to absorb sunlight. For example, melanin, the skin pigment that protects darker-skinned individuals from sunburn, works by absorbing the same UVB rays required to create vitamin D. This means that people with higher melanin levels will need more UVB exposure than their fair-skinned counterparts to produce the same levels of vitamin D. Sunscreens containing SPF 30+ work similarly, and have been reported to reduce vitamin D production by as much as 95-98%. 

Vitamin D for Cancer Prevention and Treatment

Though traditionally only associated with bone health, recent research has shown that cells throughout the body have vitamin D receptors, giving it an influential role in many internal processes. As more research illuminates the full scope of vitamin D’s benefits and abilities, scientists are beginning to understand how the populations’ decreasing vitamin D levels affect the increasing rate of cancer development, leading to thousands of premature deaths from the disease. According to an article in the Harvard Health Publishing website, “Laboratory experiments suggest [vitamin D] helps prevent the unrestrained cell multiplication that characterizes cancer by reducing cell division, restricting tumor blood supply (angiogenesis), increasing the death of cancer cells (apoptosis), and limiting the spread of cancer cells (metastasis).”

Optimal levels of vitamin D for cancer prevention and treatment may vary depending on a patient’s age, weight, medical history, cancer type (if applicable), and other individual characteristics. For reference, the U.S. Institute of Medicine considers 20 ng/ml to be the threshold for vitamin D deficiency, with ratios below this level proving dangerous to bone health. The institute recommends a minimum daily intake of 400-800 IU for most adults. However, to guarantee proactive sufficiency, intake levels may differ. The Endocrine Society suggests aspiring to a level of 40-60 ng/ml for best results, with subsequent research supporting doses of 800-1000 IU as the ideal, and doses even as high as 2,000 IU considered safe. Be sure to consult with a professional nutritionist to determine the optimal dosage for your needs. 

Best Sources of Vitamin D

Once you’ve determined the quantity of vitamin D that’s right for you, you may be wondering how to obtain it. There are three main sources of vitamin D: 

  • Sunlight: The easiest and most natural way to obtain high levels of vitamin D is through solar exposure. Fair-skinned individuals can obtain healthy levels of vitamin D by practicing safe exposure to sunlight for approximately 10-30 minutes around midday, three to five times per week. Those with higher melanin levels may require additional exposure time ranging from 30 minutes to 3 hours.
  • Diet: Certain foods, such as oily fish, shellfish, and egg yolks, are a natural source of vitamin D. However, these typically deliver much smaller quantities and should not be relied on for the bulk of vitamin D consumption.
  • Supplements: For individuals concerned with the risks of sun exposure or who find it difficult to obtain their recommended dose through natural means, vitamin D can also be obtained from plant supplements. Many daily multivitamins can provide the required levels for optimum health. 

For the best use of vitamin D in your cancer prevention and treatment strategy, newer research suggests introducing vitamin K — and specifically, vitamin K2 — to your dietary routine as well. While vitamin D increases the body’s absorption of calcium in the blood, vitamin K2 directs that calcium to concentrated areas where they will be most beneficial and prevents toxic calcium buildup in soft tissues and arteries. Vitamin K can be obtained naturally through most leafy greens, vegetables, fermented foods, and dietary supplements, and is recommended at a dose of 90 mcg for adult women and 120 mcg for adult males. 


Need More Information on Vitamin D?

Check out these additional resources to learn more about how vitamin D can play an important role in your cancer prevention or treatment strategy: 

Vitamin D and Lung Cancer

The Role of Vitamin D in Cancer Prevention

Low Vitamin D Levels: Breast Cancer Risk Factors

The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health



  1. Garland, Cedric F et al. “The role of vitamin D in cancer prevention.” American Journal of Public Health vol. 96,2 (2006): 252-61. doi:10.2105/AJPH.2004.045260
  2. Umar, Meenakshi et al. “Role of vitamin D beyond the skeletal function: a review of the molecular and clinical studies.” International Journal of Molecular Sciences vol. 19,6 1618. 30 May, 2018, doi:10.3390/ijms19061618 
  3. Sahota, Opinder. “Understanding vitamin D deficiency.” Age and ageing vol. 43,5 (2014): 589-91. doi:10.1093/ageing/afu104 
  4. Wacker, Matthias, and Michael F Holick. “Sunlight and vitamin D: a global perspective for health.” Dermato-Endocrinology vol. 5,1 (2013): 51-108. doi:10.4161/derm.24494
  5. Hossein-nezhad, Arash, and Michael F Holick. “Vitamin D for health: a global perspective.” Mayo Clinic proceedings vol. 88,7 (2013): 720-55. doi:10.1016/j.mayocp.2013.05.011
  6. “Vitamin D And Your Health: Breaking Old Rules, Raising New Hopes – Harvard Health”. Harvard Health Publishing, 2020,
  7. Tello, Monique. “Vitamin D: What’s the ‘right’ level?”. Harvard Health Blog, 2016, Accessed 5 Mar 2020.
  8. Holick, Michael F et al. “Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline.” The Journal of Clinical Endocrinology & Metabolism, Volume 96, Issue 7, 1 July 2011, Pages 1911–1930,
  9. Vieth R et al. “The urgent need to recommend an intake of vitamin D that is effective.” Am J. Clin Nutr. 2007 Mar;85(3):649-50.
  10. van Ballegooijen, Adriana J et al. “The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review.” International journal of endocrinology vol. 2017 (2017): 7454376. doi:10.1155/2017/7454376

“Office Of Dietary Supplements – Vitamin K”. Ods.Od.Nih.Gov, Accessed 5 Mar 2020.

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