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Prostate
Health & Vitamin D
May 4, 2007
Normal prostate cells are one of the sites where calcidiol converts
to calcitriol. This is important to prostate health because when
vitamin D levels are too low, the risk of benign prostatic hypertrophy
or BPH rises. Why? Well, calcitriol slows the growth of prostate
cells, keeping the gland normal in size.
One very interesting recent observation is that prostate cancer
cells lose this capacity to convert calcidiol to calcitriol.
And there’s now extensive evidence that calcitriol suppresses
prostate cancer cell growth. When prostate cells become cancerous,
they lose the capacity to manufacture calcitriol from calcidiol.
Because many prostate cancer cells do not make their own calcitriol,
the only way they get exposed to the compound is through calcitriol
in the blood stream. This fact explains why many epidemiology
studies link calcitriol to metastatic prostate cancer risk or
death from prostate cancer. In fact, Giovannucci and colleagues
at the Harvard School of Public Health found that the risk of
metastatic prostate cancer was significantly lower if a man’s
calcitriol blood level was above 40 pg/ml.
While calcitriol alone can slow prostate cancer growth in patients,
this active form of vitamin D also changes the cancer in ways
that make it more sensitive to other forms of cancer treatment.
The most dramatic example of this is calcitriol’s impact
on taxotere’s activity (Docetaxel). Adding high dose calcitriol
one day prior to taxotere nearly doubles the response rate to
this chemotherapy drug with very little increase in side effects.
When prostate cancer involves bone, it increases the amount of
calcium deposited at the site of involvement; this increase comes
at the expense of the rest of the skeleton. For this reason,
men with prostate cancer often develop osteopenia or osteoporosis
in the rest of their skeleton. In advanced prostate cancer, the
flow of calcium into the involved bone sites can be so great
that patients suffer from an abnormally low blood calcium level.
The body responds to this challenge by producing parathyroid
hormone, a hormone that breaks down bone to liberate enough calcium
to restore normal blood levels of this mineral. Not only does
this process accelerate the destruction of the bone not involved
in the cancer, but also it causes bone pain. Calcitriol is a
very effective treatment for an elevated parathyroid hormone
level and can significantly slow bone breakdown as well as lessening
the generalized bone discomfort.
For all of these reasons, I don’t think that there is any
controversy about the fact that it is important for prostate
cancer patients to maintain an adequate calcitriol blood level.
The major controversy is how best to do this.
To read more about Vitamin D and prostate cancer, click
here to purchase Volume 9 Issue 2. |
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