Study: Vitamin D supplementation needs may differ across ethnicities

CHICAGO — In a multiethnic group of adults, low vitamin D concentration was associated with increased risk of coronary heart disease events among white or Chinese participants, but not among black or Hispanic participants, according to a study in the July 10 issue of JAMA.

“Low circulating concentrations of [vitamin D] have been consistently associated with increased risk of clinical and subclinical coronary heart disease," noted lead researcher Cassianne Robinson-Cohen of the University of Washington. "Whether this relationship is causal and modifiable with vitamin D supplementation has not yet been determined in well-powered clinical trials, which are ongoing."

According to the report, most vitamin D studies examining heart disease risk have included populations that are composed largely of white participants. Results from these studies are frequently extrapolated to multiracial populations, Robinson-Cohen suggested. "This may not be appropriate because vitamin D metabolism and circulating 25 (OH)D concentrations vary substantially by race/ethnicity.”

“Well-powered clinical trials are needed to determine whether vitamin D supplements have causal and clinically relevant effects on the risk of [coronary heart disease]," Robinson-Cohen suggested. "Currently, at least five such trials are under way. One of these trials, the Vitamin D and Omega-3 Trial (VITAL), is targeting enrollment of a large multiracial study population."