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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.

Review: vitamin D and breast cancer research

Scientists have now published more than 700 scientific papers on vitamin D and breast cancer. More to the point, 37 clinical trials on the topic are now currently registered, all looking to answer two questions: Does vitamin D help prevent breast cancer, and two, does vitamin D have any treatment effect in established breast cancer?

If you read the obituaries in your local newspaper, you will find numerous women, dead in their 40s and 50s, dead before their time, and too often, the culprit is breast cancer. The lifetime risk for breast cancer in the USA is around 10% of women by age 90, with a 3% lifetime risk of dying from breast cancer. For unknown reasons, the United States has the highest rates of breast cancer in the world; 128 per 100,000 in whites, slightly less among African Americans. Breast cancer is the only major cancer that is less common in Blacks, but the disease is more aggressive in Blacks. It is the second-most common cause of cancer death (after lung cancer) in women. In 2010, breast cancer caused in excess of 40,000 deaths in the USA.

Dr. Theresa Shao and colleagues at the Beth Israel Medical Center published a great review paper in January of 2012.

Shao T, Klein P, Grossbard ML. Vitamin D and breast cancer. Oncologist. 2012;17(1):36-45. Epub 2012 Jan 10.

Other than the Lappe paper (in which 1,100 IU of vitamin D appeared to prevent a number of internal cancers), we have no randomized controlled trials to answer the questions above. Interested women everywhere must understand what is known and what is unknown and make up their own minds. As readers know, I am a great believer in waiting for the science to do its work with a natural vitamin D level (around 50 ng/ml).

First, the authors reviewed the test tube and animal studies. They are impressive. Vitamin D signals more than 100 genes to force breast cells to die (which is natural), prevent them from being undifferentiated, and prevent them from hijacking blood vessels. Therefore, animal and test tube studies are generally quite positive.

Next are ecological studies or the study of the relationships living things have to one another. Here again we have multiple studies showing areas with the most sunlight have the lowest rate of breast cancer. After that, we have dietary studies, which are virtually all negative because you simply cannot get enough vitamin D from your diet to make any significant difference.

Then we have at least eight studies of vitamin D levels and subsequent risk of breast cancer. Here, five of the eight are supportive, and two of the three negative studies are very close to positive. Few of the studies had adequate levels. The one study with natural levels reported that women with levels of  60 ng/ml or greater were almost six times less likely to get breast cancer than women whose levels were less than 20 ng/ml. As you’d suspect it was a small study: how can you find enough women with natural levels?

Then the authors discuss several studies that show women diagnosed in the summer do better than women diagnosed in the winter, a finding suggestive of a treatment effect. Another study showed that women diagnosed with breast cancer had a better prognosis if their vitamin D levels were higher, supportive of the season-of-diagnosis findings. Unfortunately, no randomized controlled trial giving meaningful doses of vitamin D, except the Lappe study, have ever been published.

An interesting study gave women with breast cancer 50,000 IU/week and found that women who achieved a blood level of greater than 60 ng/ml had less disability from joint symptoms, a common complaint with standard breast cancer therapy.

Then, Dr. Theresa Shao and colleagues at the Beth Israel Medical Center then did something quite amazing. They did not end their paper with the truism that we don’t know if vitamin D will help and more studies are needed. Instead they wrote,

“The optimal risk for reducing breast cancer risk or the risk of recurrence of breast cancer has yet to be defined, but simply targeting 25(OH)D levels known to be safe and optimal for bone health (30-50 ng/ml) might be a good start.”

I could not have said it better, although natural levels, around 50 ng/ml, might be a better start than the levels found in indoor workers in the summer (30 ng/ml). I hope the author’s summation represents a change in how scientists view cancer and vitamin D. Moreover, I hope they add a little common sense to the subject, unlike the “do nothing until randomized controlled trials prove it helps” crowd; a crowd whose hands increasingly look bloody to me.

  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.

8 Responses to Review: vitamin D and breast cancer research

  1. Yes, there are many great papers on vitamin D reducing the probability of getting cancer.
    During the past year we are seeing papers postulating HOW vitamin D does the magic
    Blog post at Vitamin DWiki: http://www.vitamindwiki.com/tiki-view_blog_post.php?postId=61
    My favorite: vitamin D might repair the DNA

  2. Perhaps I don’t remember correctly. Shouldn’t posts be free accessible after a given time? (six months?) O course I can access them but I would like to be able to link to them.

    • Brant Cebulla says:

      Serdna, thanks for the feedback. We have thought about something like this but are still trying to build our member base for the time being and keeping things closed. Another challenge is implementing such a system, as their are some technological barriers in developing such a feature.

      Also keep in mind that some blogs are open access and we definitely encourage members to share those open access papers. Currently, the only way to know if a blog is open access is by logging out and seeing which blogs are still view-able in-full. We have some ideas how to make this more usable, but feedback in this regard is welcome, too.

      Cheers, Brant

  3. Ok! It seems that technology is in the way sometimes. Thanks for answering.

  4. Rita and Misty says:

    Dr. Cannell, I’m sorry that I missed this piece back on February 16th; but, I am certainly glad to read it now.

    Like so many of your articles, it holds more (and more) truth as time goes on…and although you wrote the above blog back in February, with the recent news about Angelina Jolie’s decision for a double-mastectomy, your words of wisdom seem and common sense seem additionally appropriate today.

    Readers here know that I choose to keep my 25(OH)D level at the higher end of optimal. I make this decision, in part, because I do hope that it will keep me from developing breast cancer.

    I have already had two benign tumors removed: one at age 28 and one at age 36. I am 48 currently. Who knows what the future holds? I choose not to dwell on such things. But, rather, I do my best to keep as healthy as possible.

    This is a personal decision I have made based on the research I have done. I am not a health care professional (though I do wish I were), nor am I a scientific researcher. I am someone who simply tries to keep informed, and apply a bit of sanity to my life.

    I understand full well that we have yet to find a cure for death. I strive to live my life as healthy and productive as possible.

    And keeping an optimal 25(OH) D plays an important role for me in this aspect.

    I recently posted some information on vitamin d with respect to the BRCA gene on another VDC posting. I hope readers are okay with me posting it here as well:


    As taken from the above link:

    The Fix
    If lowering the levels of 53BP1 allows BRCA1 deficient cells to thrive and do their worst, increasing the levels of the protein offers a promising strategy for treatment of breast tumors.

    So, how to do this? In previous research, Gonzalo’s team showed that vitamin D inhibits CTSL-mediated degradation of 53BP1 in non-tumor cells, as efficiently as specific CTSL inhibitors. This time, they found that treatment of BRCA1-deficient tumor cells with vitamin D restores high levels of 53BP1, which results in increased genomic instability and reduced proliferation. Importantly, their evidence suggests that vitamin D treatment might restore the sensitivity to PARP inhibitors in patients who become resistant. Thus, a combination of vitamin D and PARP inhibitors could represent a novel therapeutic strategy for breast cancers with poor prognosis.

    So, with this chain of events, Gonzalo and colleagues demonstrated a pathway by which triple-negative breast cancers proliferate: BRCA1-deficient cells activate CTSL which minimizes levels of 53BP1 to overcome genomic instability and growth arrest.

  5. IAW says:

    Thanks for all your hard work Rita! I missed the first posting!

  6. Rita and Misty says:

    @ IAW, I appreciate your kind words…glad the information is useful to you! :)

    @Sernda, I sent you an email at your gmail address.

  7. markperosi123@aol.com says:

    Amazing D3 so powerful….thank you D-council………you have helped me learn the truth. I pass this info to all who want to hear. My wife makes it a point when you go to party’s do not bring up vitamin D3. Nobody wants to hear you preach. So I don’t. Then the topic is brought up by others. Interesting they all start to take notes. I have been thanked by members of the Local YMCA for helping them feel better after taking D3. And for educating doctors who don’t have time to read the medical journals.