Sunlight, Vitamin D & Prostate Cancer [Hardcover]

P. J. Hyde (Author)

Book Description

ISBN-10: 1401082599 | ISBN-13: 978-1401082598 | Publication Date: April 2, 2004

Summary This science-based book is the first to demonstrate that insufficient access to the sun's ultraviolet-B (UV-B) irradiance, necessary for photosynthesis of vitamin D, increases the risk of progression in prostate cancer.

At least 80 per cent of our major circulating reservoir of the vitamin, 25-hydroxyvitamin D, is produced by casual exposure of unprotected skin to solar UV-B. The remainder is obtained from foods and supplements.

The author looks at five of the many populations characterized by elevated death rates from prostate cancer: African-North Americans, Norwegians, Swedes, Swiss, and Danes. He shows that insufficient photosynthesis is common to them all and describes the causative circumstances in each instance.

An in-depth review of the literature revealed that a substantial increase in the daily supply of vitamin D recommended for adult North Americans is urgently needed. Importantly, it showed that an increase of the magnitude envisaged would fall well within the range of values necessary for combining safety and efficacy.

The following examples illustrate the scope and tenor of the book:

· Evidence that calcitriol, a steroid hormone metabolized from 25-hydroxyvitamin D, inhibits proliferation of prostate cancer cells, as well as regulating the supply of calcium to bones and other organs.

· The capacity of calcitriol to induce cell cycle arrest (apoptosis) and decrease the harmfulness of insulin-like growth factors (IGF), known to be implicated in cancers of the prostate, the breast, and the colon.

· The significance of the term "gene-expression switch," considered in the light of the ability of calcitriol and its receptor to modulate the transcription of numerous genes within the nuclei of cells.

· Provided that two prerequisites are met, the ability of the prostate to produce calcitriol within its cells.

· Details of an actual case of vitamin D toxicity after long-term mega-dosing with a

Editorial Reviews

From the Publisher

WHAT PEOPLE ARE SAYING

Edward Napke, B.Sc., M.D., D.P.H., Queen Elizabeth's Anniversary Medal (QEAM) This is a remarkable book that could be helpful in lowering the risk of prostate cancer and its progression in individuals subject to deficient circulating concentrations of vitamin D3 and its biologically active metabolites. The deficiencies are mainly the result of insufficient exposure to solar short wavelength ultraviolet-B radiation, without which vitamin D3 cannot be photosynthesized. Reinforcing this are inadequate intakes of supplementary vitamin D3 and the foods that contain it.

After acknowledging that many factors are implicated in prostate cancer, the author cites approximately 100 studies reported in scientific journals and reproduces geographically significant disease-specific statistics of mortality extracted from publications of the WHO and its affiliate, the IARC (International Agency for Research into Cancer).

The information thus assembled indicates that in countries in the northern and southern hemispheres, vitamin D3 deficiency is an overlooked environmental risk factor of major importance, particularly in middle-aged and elderly men whose place of residence is in the middle and higher latitudes (40 degrees and higher). Bibliographic references are given for all of the sources cited.

Despite the importance of the work in drawing attention to the dangers of vitamin D3 deficiency, not only with respect to prostate cancer but also to breast cancer, colorectal cancer, multiple sclerosis, type 1 diabetes, a variety of bone diseases and a growing list of other disorders, little is said about the author's personal experience with prostate cancer and bladder cancer, diagnosed in 1984 and 1986.

We sense that a gripping story has been left untold and must remain in the dark until this is done. There is a "hole in the narrative" that lessens the human and personal appeal of the book. I have brought this to the attention of the author, who is willing to rectify the omission in any subsequent edition.

My main criticism, however, is that he fails to distinguish consistently between the so-called "sunshine vitamin," namely vitamin D3 (cholecalciferol), the history of which is summarized, and vitamin D2 (ergocalciferol), a substance derived from yeasts and plants. All too often readers are expected to make do with the non-specific term vitamin D, when what is actually being discussed is D3.

It is from vitamin D3 that minute quantities of a short-lived, powerful steroid hormone, 1 alpha,25-dihydroxyvitamin D3 (calcitriol), are repeatedly metabolized from the body's limited store of calcidiol, (25-hydroxyvitamin D3), its major circulating reservoir of the vitamin. The book shows that when the blood supply of calcidiol begins to wane, which tends to occur in the elderly in the late winter and early spring, there is a corresponding decrease in the concentration of calcitriol.

That is why residents of countries in the middle and high latitudes, particularly those where the winters are long and cold, need to build up a supply of calcidiol during the warm season sufficient to last the whole of the coming winter.

When circumstances prevent this, ensuring adequate daily intakes of vitamin D3- rich foods and supplements can be crucial. Readers are informed that their daily requirement of vitamin D3, expressed in international units, may be greatly in excess of the quantities they are actually obtaining, from sun exposure and nutrition.

African-North Americans and Afro-Caribbeans are shown to be at exceptionally high risk of deficiency. It is in these populations that the incidence and mortality rates of prostate cancer are reported to be the highest in the world.

The benefits derivable from adequate circulating concentrations of calcitriol in another common cancer are strikingly apparent in the results of a six-months long in-hospital study of female breast cancer patients. Some of the findings of that study are included in the closing pages of the book (Appendix D). The information we are given is compelling. - Edward Napke, B.Sc., M.D., D.P.H.,

Product Details

• Hardcover: 280 pages
• Publisher: Xlibris Corporation (April 2, 2004)
• Language: English
• ISBN-10: 1401082599
• ISBN-13: 978-1401082598
• Product Dimensions: 8.5 x 5.5 x 0.8 inches
• Shipping Weight: 1.1 pounds (View shipping rates and policies)
• Amazon Best Sellers Rank: #6,016,236 in Books (See Top 100 in Books)

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