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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.

Vitamin D supplements significantly reduce Ki67 in prostate cancer cells

For decades, scientists have been trying to increase the amount of activated vitamin D in cancer cells, in the hope that it will slow cancer’s growth, without causing high blood calcium at the same time. In many ways, activated vitamin D is the ideal anticancer drug, as it forces cells to die when they are supposed to do so (apoptosis) and it increases specialization (differentiation) of cells, unlike cancer cells that try to avoid dying and are often highly undifferentiated.

Although many cancers destroy the vitamin D system as soon as they can, not all cancers do. That is, some cancer cells retain both the enzymes and the receptors needed for the vitamin D system to work. Therefore, beginning in the 1980s, the search was on for an activated vitamin D-like molecule that would go inside cancer cells but not cause high blood calcium at the same time.

The struggle to increase activated vitamin D in cancer cells has led scientists to develop several hundred analogues (variations to the molecule that allow scientists to patent it) of activated vitamin D. However, all analogues to date are problematic because they still cause high blood calcium. Furthermore, they do not get inside cancer cells to the degree needed to kick the vitamin D system into high gear. If they do, blood calcium levels become dangerously high.

At the April 2012 meeting of the American Association for Cancer Research, Professor Reinhold Vieth and his group reported taking another approach. Instead of giving activated vitamin D or its analogues, they simply gave increasing doses of plain old vitamin D in hopes the cancer cells would take up 25(OH)D and make high amounts of activated vitamin D inside the cell.

Oral Vitamin D Supplements Reduced Levels of Ki67 in Prostate Cancer Cells. ScienceDaily (Mar. 31, 2012)

They first randomized 66 men scheduled for removal of a cancerous prostate (radical prostatectomy) to one of 3 doses of plain vitamin D: 400, 10,000 or 40,000 IU/day. They administered these doses for three to eight weeks before the surgery. Then, after the surgery, they measured the amount of activated vitamin D inside the prostate cancer, as well as two “markers” of cancer growth.

To everyone’s surprise (except perhaps Professor Vieth?), his group found that activated vitamin D levels inside the cancerous prostate increased significantly with each increasing dose of plain vitamin D. 40,000 IU/day resulted in the highest levels of activated vitamin D inside the prostate cancer. These higher levels of activated vitamin D inside the cancer were associated with significantly lower levels of a “bad” marker (Ki67, a protein that indicates prostate cancer cell growth) and higher levels of a “good” marker, one having to do with growth inhibition of the cancer.

This is an exciting discovery. It means that plain vitamin D may help slow the growth of some cancers. If you are scheduled for prostate cancer surgery, Professor Vieth does not advise you to take 40,000 IU of vitamin D/day for 2 months before the surgery. However, I can advise you to keep your vitamin D levels in the high range of normal (70-90 ng/ml), which will mean about 10,000 IU/day for most men.

Remember that in 2009, a Norwegian group found that “high” vitamin D levels at the time of diagnosis of prostate cancer were associated with remarkable reductions in subsequent death rates (RR=.09).

Tretli S, Hernes E, Berg JP, Hestvik UE, Robsahm TE. Association between serum 25(OH)D and death from prostate cancer. Br J Cancer. 2009 Feb 10;100(3):450-4.

As the authors said, “To conclude, this study shows a strong association between 25(OH)D levels and mortality in patients with prostate cancer.” They classified “high” vitamin D levels as anyone above 32 ng/ml, levels easily achieved with 5,000 IU per day in just about everyone, regardless of their weight or genetics.

  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.

2 Responses to Vitamin D supplements significantly reduce Ki67 in prostate cancer cells

  1. eelisabethpuur@gmail.com says:

    I still don´t get why they use the active calcitriol form. I just can´t get this question about money out of my head. When D3 is so cheap?
    Do I understand it right? … they have one group with soy, one with calcitriol and one with the combination? but no group with D3? what happend in the calcitriol-group? If the risk of hypercalcemia is bigger with calcitriol, and everyone knows it, why use it?

    Look at this; “Soy increases the bioavailability of endogenous and administered calcitriol, thereby enhancing its anticancer effects and risk of hypercalcemia. Since both agents are easily available as dietary supplements, the increased potential for hypercalcemic toxicity becomes an important factor when considering the combined use of vitamin D and soy in PCa therapy.”

    Firts they talk about the activated, the calcitriol, but in the end they talk about soy and vitamin D, do they mean vitamin-over-the-counter-D3? as the calcitriol is a prescription drug …
    I know it´s a mouse study … but … who paid for this study?


    These supplements fight prostate cancer
    04/14/2012 20:24:00admin
    These supplements fight prostate cancer

    By David Liu, PHD

    Saturday April 14, 2012 (foodconsumer.org) — Vitamin D and soy may have a protective effect against prostate cancer and a new study in the March 27, 2012 issue of the journal Prostate suggests that a combination of vitamin D in the active form 1,25(OH)(2)D can be enlisted to prevent or treat prostate cancer.

    The study led by J.Y. Wang and others from Stanford University School of Medicine in Stanford California found that combination treatments based on soy and calcitriol, the active form of vitamin D resulted in substantially greater inhibition of tumor growth than either soy or calcitriol in athymic male nude mice bearing PC-3 human prostate cancer xenografts.

    In the study, the mice received diets containing 10 or 20% of calories from soy, calcitriol injections or a combination of soy and calcitriol. The mice were monitored for their tumor growth, serum levels of a,25(OH)(2)D and calcium and regulation of tumor gene expression.

    The researchers found the following:

    “Soy diets alone caused a modest elevation in serum 1,25(OH)(2) D, whereas the calcitriol-soy combinations led to substantially elevated serum 1,25(OH)(2) D, hypercalcemia, and in some cases lethal toxicity. The combinations enhanced calcitriol activity in regulating target gene expression, including greater up-regulation of anti-proliferative (p21, IGFBP-3) and pro-apoptotic (Bax) genes, increased inhibition of anti-apoptotic (Bcl-2) and cell cycle promoting (cyclin D1) genes, and suppression of prostaglandin (PG) synthesis and signaling (COX-2, 15-PGDH, PG receptors). Increases in serum calcium were accompanied by elevated expression of intestinal calcium absorption genes (TRPV6, calbindin-9k).”

    They concluded that

    “Soy increases the bioavailability of endogenous and administered calcitriol, thereby enhancing its anticancer effects and risk of hypercalcemia. Since both agents are easily available as dietary supplements, the increased potential for hypercalcemic toxicity becomes an important factor when considering the combined use of vitamin D and soy in PCa therapy.”

    Using calcitriol, which is only available through doctors, is risky because this active form of vitamin D unlike the form of vitamin D sold as dietary supplements can have a direct influence on many physiological functions. One common risk of hypercalcemia, which is a common concern associated with use of vitamin D. It’s well recognized that high doses of vitamin D may be used to fight cancer, but the potential risk is hypercalcemia.

    There are many things a man can do to reduce his risk of prostate cancer. The cancer is generally growing fairly slowly and a man older than 70 may be more likely to die from another disease. For that reason, men may be better off not receiving any screening and treatment, which can do more harm than good for men ages 70 or older.

  2. Umileritac@aol.com says:

    The oncologist rarely hesitates at treating cancer with chemotherapy, regardless of the plentiful negative side effects. It seems to me that these side effects from chemotherapy are considered “a given” by the oncologist. It is like an unspoken dilemma: you have cancer–do you want to have the potentially deadly treatment or to potentially die from the cancer? Enter Vitamin D3 and all its benefits….Why would any sane doctor fight its use, even at very high levels? Certainly there is the risk of hypercalcemia. But, what treatment is risk free?