A connection between vitamin D level and the risk of developing breast cancer has been implicated for a long time, but its clinical relevance had not yet been proven. Sascha Abbas and colleagues from the working group headed by Dr. Jenny Chang-Claude at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), collaborating with researchers of the University Hospitals in Hamburg-Eppendorf, have now obtained clear results: While previous studies had concentrated chiefly on nutritional vitamin D, the researchers have now investigated the complete vitamin D status. To this end, they studied 25-hydroxyvitamin D (25(OH)D) as a marker for both endogenous vitamin D and vitamin D from food intake.
The result of the study involving 1,394 breast cancer patients and an equal number of healthy women after menopause was surprisingly clear: Women with a very low blood level of 25(OH)D have a considerably increased breast cancer risk. The effect was found to be strongest in women who were not taking hormones for relief of menopausal symptoms. However, the authors note that, in this retrospective study, diagnosis-related factors such as chemotherapy or lack of sunlight after prolonged hospital stays might have contributed to low vitamin levels of breast cancer patients.
A prospective study that tracks the blood vitamin D level of lots of women for years would be more definitive. But such studies are much more expensive. Another way to get at the question: a study that checks vitamin D levels at the time of mammograms for women with suspicious lumps. The blood samples could be held and not tested for vitamin D until mammogram results are known. That would reduce the number of vitamin D tests done on women without breast cancer.
|Share |||Randall Parker, 2008 April 20 10:15 AM Aging Diet Cancer Studies|