Sunlight, Vitamin D & Prostate Cancer
by P. J. Hyde, published by Xlibris Corporation (2004-04-30)Buy now from Amazon.com for $31.99
Amazon rating of Not Available out of 5, Amazon sales rank: 1179889
Editor's Review:"Sunlight, Vitamin D & Prostate Cancer Risk" P. J. Hyde Synopsis This science-based book is the first to demonstrate that in prostate cancer, insufficient access to the sun's short wavelength ultraviolet-B (UV-B) irradiance, necessary for photosynthesis of vitamin D, increases the risk of progression. It explains why, even though excessive exposure to UV-B can lead to non-melanoma skin cancers, the effects of prolonged interruptions in its availability must be pre-empted by ensuring adequate exposure to sunlight in summer, and in countries with long cold winters, by substantial increases in vitamin D supplementation. With a background in science translation, the author decided to write the book after being diagnosed with prostate cancer at age 60 and witnessing the tragic loss of life from the disease among his less fortunate friends and contemporaries. After learning that a vitamin D-deficiency hypothesis for prostate cancer had been successfully tested in the 48 adjoining states of the USA, he embarked on an epidemiological research project embracing Western European, South-East Asian and Australasian populations. He looks closely at four populations with steeply elevated prostate cancer death rates: African-North Americans, Norwegians, Swedes and Swiss. He finds that insufficient exposure to the sun's UV-B and resulting vitamin D deficiency is common to them all. Statistics of age-specific rates of prostate cancer mortality in Western European countries were extracted from World Health Statistics Annuals published by the World Health Organization (WHO); tabulated and converted to graphs. The Swiss rates were found to be abnormally high for the latitude. Statistics of age-standardized (world) rates published by the International Agency for Research into Cancer (IARC) in its Globocan 2000 Cancer Epidemiology Database confirm the existence of an anomaly. Identical prostate cancer mortality rates are recorded for Norway, Sweden and Switzerland. In summer, a large fraction of the incoming UV-B is prevented from reaching the cities on the Central Plain of Switzerland. The main causes are reflection back into space by perpetually snow-capped mountains, and scattering and absorption at low altitudes by humidity, ground-level ozone and aerosols. Additionally, the Swiss diet is poorly supplied with vitamin D nutrients and public interest in supplementation is minimal. The fact that no anomalies are indicated for the countries surrounding Switzerland: Austria, France, Germany and Italy, most of whose citizens reside far from the Alps, adds weight to the evidence that vitamin D deficiencies increase the risk of progression. The book describes how minute quantities of a powerful steroid hormone (calcitriol), metabolized from 25-hydroxyvitamin D (calcidiol), bind to the hormone's receptors (VDR) within the nuclei of cells. Together, calcitriol and the VDR induce the cells to differentiate, thereby inhibiting cellular proliferation and tumour growth. The foregoing information leaves no doubt that protracted interruptions in the accessibility of UV-B, and insufficient vitamin D supplementation in winter, are directly implicated in the etiology and progression of prostate cancer. "Recommended reading for anyone interested in lowering their risk of prostate cancer"---Christopher Morash, MD, FRCSC, Chief of Urosurgical Oncology, Ottawa Regional Cancer Centre, Ottawa, Ontario. Reader Reviews: Not Available
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