Despite hopes that higher blood levels of vitamin D might reduce cancer risk, a large study finds no protective effect against non-Hodgkin lymphoma or cancer of the endometrium, esophagus, stomach, kidney, ovary, or pancreas. In this study, carried out by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, and many other research institutions, data based on blood samples originally drawn for 10 individual studies were combined to investigate whether people with high levels of vitamin D were less likely to develop these rarer cancers. Details of these analyses appear as a set of papers in the June 18, 2010, online issue of the American Journal of Epidemiology, and in print in the July 2010 issue.
“We did not see lower cancer risk in persons with high vitamin D blood concentrations compared to normal concentrations for any of these cancers,” said Demetrius Albanes, M.D., NCI, one of the study investigators. “And, at the other end of the vitamin D spectrum, we did not see higher cancer risk for participants with low levels.”