VDC test kit slider
VDC test kit slider
sperti logo 1
Text size A A A
High contrast on off

Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Vitamin D, breast cancer, and chemotherapy: A look at the research

In 2008, breast cancer killed 458,503 women worldwide. The incidence of breast cancer varies greatly around the world; the further you live from the equator, the higher the risk. Rates have increased significantly since the 1970s.

In 2009, Professor Cedric Garland’s group at the University of California at San Diego estimated that maintaining a 25(OH)D level between 40-60 ng/ml would prevent 75% of new cases in the USA.

Garland CF, Gorham ED, Mohr SB, Garland FC. Vitamin D for cancer prevention: global perspective. Ann Epidemiol. 2009 Jul;19(7):468-83. Review.

However, vitamin D deficiency among breast cancer patients remains rampant. Dr. William Jacot and colleagues from Montpellier, France, recently measured vitamin D levels in 77 breast cancer patients. They found that 80% of all patients at the time of diagnosis were vitamin D deficient (<30 ng/ml) with 40% having levels below 20 ng/ml and 10% had levels below 10 ng/ml.

Jacot W, Pouderoux S, Thezenas S, Chapelle A, Bleuse JP, Romieu G, Lamy PJ. Increased prevalence of vitamin D insufficiency in patients with breast cancer after neoadjuvant chemotherapy. Breast Cancer Res Treat. 2012 May 6.

Regrettably, after 18 months of standard chemotherapy, a period that included two summers, vitamin D levels were remarkably lower. After chemotherapy, 97% of all patients were deficient, with 50% below 20 ng/ml and almost one-fourth below 10 ng/ml. What happened to their vitamin D?

One explanation is that the women stopped going outside after diagnosis or that the chemotherapy drugs interacted with vitamin D. However, another explanation is that the breast cancer used up the vitamin D in fighting the breast cancer. Indeed, the authors state, “Many data support the hypothesis that vitamin D might have anti-cancer activity in breast cancer.”

To be sure, studies confirm that at diagnosis, patients with higher levels of vitamin D do better and live longer, and this includes breast, lung, colon, and prostate cancer This implies a treatment effect.

Goodwin PJ, Ennis M, Pritchard KI, Koo J, Hood N. Prognostic effects of 25-hydroxyvitamin D levels in early breast cancer. J Clin Oncol. 2009 Aug 10;27(23):3757-63. Epub 2009 May 18.

I do not understand why we must wait for randomized controlled trials while these women suffer and die. It appears from the above study by Jacot et al that some oncologists may not be giving any vitamin D at all. Instead, they are letting levels fall into the osteomalatic (adult rickets) range during chemotherapy. And osteomalacia is a painful disease.

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

3 Responses to Vitamin D, breast cancer, and chemotherapy: A look at the research

  1. Yes, vitamin D gets used up in fighting many attacks on the body, such as cancer, surgery, trauma, and even earthquakes.
    Yes, extra vitamin D is important to have during all of those situations: http://www.vitamindwiki.com/tiki-browse_categories.php?parentId=64&sort_mode=created_desc
    BUT, be careful with extra vitamin D with Chemotherapy. Vitamin D amplifies many Chemo therapies by about 3X – which is great if the doctor will reduce the chemo dose by 3X, but can be lethal if the doctor keeps with the chemo dose which had been developed for most of the population, who are vitamin D deficient. See the data and the chart of your 4 options for vitamin D and chemotherapy http://is.gd/chemoD

  2. I know this 17 or 18 years old lady that had stage 4 cancer in her digestive region who had been taking 10,000 IU of D3 a day at the recommendation of her oncologist (based in Dallas-Ft Worth) while undergoing chemotherapy (not sure how many rounds, maybe 18 total?).

    She looked remarkable healthy the entire time and she beat stage 4 cancer. You’d never know she had cancer the whole time.

  3. jmeshon says:

    Regarding the comment above by hlahore – it would seem that more vitamin D along with a reduction in chemotherapy should be studied. If it could be as effective one would think it would be far less tramautic to patients’ systems.