Friday, July 12, 2013
Low vitamin D blood levels are linked to greater risk of heart disease in whites and Chinese, but not in blacks and Hispanics
Growing evidence has suggested that low blood levels of 25-hydroxyvitamin are associated with higher risk of developing coronary heart disease among whites. Few of these studies included substantial numbers of people from other races. Vitamin D levels tend to be lower among people from other racial and ethnic minority groups, and some of these populations have higher rates of heart disease. However, after correcting for other risk factors for heart disease in their large, multi-ethnic study group, researchers did not find an association between low vitamin D and cardiovascular events in their black and Hispanic study participants. "Our study suggests that the results of ongoing vitamin D clinical trials conducted in white populations should be applied cautiously to people of other racial and ethnic backgrounds," said Cassianne Robinson-Cohen. "Our future studies will examine the genetics affecting the levels and use of Vitamin D in the body to try to figure out why the link between low vitamin D blood levels and heart disease varies by race and ethnicity," she said. "We don't know for sure, but perhaps genes affecting the need for and use of vitamin D could have evolved to adapt to different levels of sun exposure in places where various ethnic subgroups of people originated." Her team plans to look for variations in genes known to mediate Vitamin D activation and metabolism. She said that these genes have been identified, but at present scientists haven't determined how gene variation influences susceptibility to the adverse effects of low vitamin D.