Tuesday, May 7, 2013

Clinical trial: Vitamin D in the prostate

Clinical trial: Vitamin D in the prostate
March 28, 2013 -- John Cannell, MD

Professor Reinhold Vieth at the University of Toronto is one of my heroes. It was his 1999 review paper on vitamin D, which I must have read ten times, a paper freely available for all to read, that first convinced me vitamin D would change the face of modern medicine. He outlined the difference between physiological doses (up to 10,000 IU/day) and pharmacological doses (50,000 to 100,000 IU/day), writing that pharmacological doses would have been studied long ago if vitamin D was a drug that could be patented.

So far, only patentable and expensive analogues of activated vitamin D have received the financial support to undergo the sort of rigorous testing needed to be approved as therapeutic agents by the FDA. They have been studied in a variety of illnesses, mostly cancer, but with minimal success. The key issue is how much activated vitamin D one can get into a cancerous tumor, say prostate cancer, by giving an activated vitamin D analogue.

Normally, the amount of activated vitamin D in a tissue like the prostate is largely determined by its regulated production within that tissue. What has been discovered the hard way, has been that the approach of providing the activated vitamin D by mouth so that some of it reaches the prostate, actually ends up overdosing the whole body when all you want to do is affect the prostate. What has never been answered is whether you can increase the amount of activated vitamin D in a tumor, like prostate cancer, simply by providing the body with enough plain vitamin D so that the tissue has enough to take care of its own needs.

The prostate gland is one of the few organs that can both make 25(OH)D and activate it as well. Unlike some other cancers, many prostate cancers retain the ability to activate vitamin D, so theoretically you may be able to get high doses of activated vitamin D inside prostate cancer cells by simply giving plain vitamin D, although this has remained theoretical until Professor Vieth’s latest paper.

This is important in treating cancer because based on what we know from laboratory experiments is that high levels of activated vitamin D inside cancer cells produce anticancer effects. Continue reading → (no membership required)

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