Vitamin D May Lower Heart Disease Risk
Studies Suggest That Correcting Vitamin D Deficiency Improves Heart Health
March 15, 2010 (Atlanta) -- If you have low vitamin D levels, correcting the deficiency may reduce the risk for heart disease, new research suggests.
The studies build on the researchers' previous work linking low levels of vitamin D to an increased risk for heart disease.
The researchers, from the Intermountain Medical Center Heart Institute in Murray, Utah, presented the new studies at the American College of Cardiology's 59th annual scientific session.
Vitamin D vs. Heart Disease: Study Details
The first study involved more than 9,400 patients whose blood tests revealed low vitamin D levels during a routine trip to the doctor. Their average vitamin D level was 19.3 nanograms per milliliter; levels of 30 are generally considered "normal," according to J. Brent Muhlestein, MD, the Institute's director of cardiovascular research.
At their next follow-up visit, about half had raised their vitamin D levels to above 30 nanograms per milliliter.
Compared with patients whose vitamin D levels were still low, patients who raised their vitamin D levels were 33% less likely to have a heart attack, 20% less likely to develop heart failure, and 30% less likely to die over an average follow-up period of one year.
In the second study, the researchers placed more than 41,000 patients into three categories based on their levels of vitamin D -- normal, moderate deficiency, and severe deficiency. Then they combed their medical records to see who had been diagnosed with heart disease or stroke.
As expected, patients with severe deficiency were most likely to have been diagnosed with heart disease or stroke, Muhlestein tells WebMD.
Then the researchers put all the information into a computer algorithm to see if there is an optimal level of vitamin D when it comes to heart disease prevention.
"While normal has generally been considered to be 30, some people have suggested 40 or 50 is better.
"What we found is that people who increased their vitamin D blood level to 43 nanograms per milliliter had the lowest rates of heart disease and stroke. But increasing it beyond that, say to 60 or 70, offered no greater benefit," he says.