Vitamin D May Not Protect Against Prostate Cancer
Study does not rule out, however, that men with certain genetic mutations affecting the body's processing of vitamin D may have a higher risk of prostate cancer when they are deficient in the nutrient
May 21, 2009 (Reuters Health) -- New research from Europe confirms that men's prostate cancer risk has no relationship to how much vitamin D they have in their blood.
"Despite the widespread notion that vitamin D insufficiency is an important risk factor for prostate cancer, this theory has not been substantiated by results from the majority of published prospective studies," Dr. Francesca L. Crowe of the University of Oxford in Oxford, UK, and colleagues write in the American Journal of Epidemiology.
Scientists have been investigating whether insufficient vitamin D boosts prostate cancer risk ever since a 1990 study linked higher rates of the disease to lower sunlight exposure (which triggers vitamin D production in the body), Travis and her team note. However, while experiments in lab dishes and animals have supported such a relationship, they add, investigations in men living in the US and in Scandinavian countries have not.
To investigate the association in a wider European population, Travis and her team looked at men from seven different European countries who participated in the European Prospective Investigation into Cancer and Nutrition. The analysis compared 652 men who developed prostate cancer after 4 years of follow-up to 752 men who did not.
Men with the highest blood levels of vitamin D were actually 28 percent more likely to develop prostate cancer than the men with the lowest levels, the researchers found, but this wasn't a significant difference from a statistical standpoint -- meaning it could have occurred by chance.
When the researchers analyzed different subgroups of the study participants based on their cancer stage, body mass index, and other factors, there was still no association between levels of vitamin D and prostate cancer.
Some research suggests that men with certain genetic mutations affecting the body's processing of vitamin D are at risk of prostate cancer when they are deficient in the nutrient, Crowe and her colleagues note, and their findings -- which didn't include information on whether or not men had such mutations -- don't rule out this possibility.
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