Heart Dangers of Low Vitamin D Levels May Vary
Study found whites, Asians more affected than blacks, Hispanics
Ironically, blacks and Hispanics are known to have lower levels of vitamin D than their white or Asian counterparts, Norris said.
"We would think that the populations with lower vitamin D levels would be at greater risk for heart disease," but these findings suggest the complete opposite, he said.
In the study, black participants had the lowest vitamin D levels at 19.2 ng/mL. Hispanic participants had vitamin D levels of 24.6 ng/mL. By contrast, Chinese individuals had mean vitamin D levels of 26.7 ng/mL and white participants had a mean levels of 30.1 ng/ml.
The findings "reinforce the fact that we can't generalize from one group to another group whether blacks to whites, men to women or kids to adults, " Norris stressed. "We can't just grab a bunch of patients with low vitamin D, and put half on supplements and the other half on none."
The findings were published in the July 10 issue of the Journal of the American Medical Association.
While the study shows an association between low vitamin D levels and heart disease, it does not prove that there is a cause-and-effect relationship for any race or ethnicity.
The researchers did control for other heart disease risk factors such as diabetes, obesity and high blood pressure levels, but Norris speculated that "these other risk factors are not as powerful among white and Asian individuals, so vitamin D can express a more significant impact on its relationship with heart disease."
One expert said the study raises more questions than it answers.
"It just shows that in certain patients, low vitamin D might portend a higher heart disease risk while in others it is not so clear-cut, " said Dr. David Friedman, chief of heart failure services at North Shore-LIJ's Plainview Hospital, in Plainview, N.Y.
His advice is to see your doctor and get your vitamin D levels tested. If they are low, supplementing may make sense for bone health, and possibly heart health. "Make sure all of your other heart disease risks are in the normal range, too," he said.