KALAMAZOO — Vitamin D is known to help the body absorb calcium so its impact on bone health is well documented. But more and more research indicates that vitamin D may also have an impact on heart health.

As a result, some area health-care providers are measuring and evaluating vitamin D levels as standard protocol when working with high-risk heart patients.

Dr. Soundos Moualla, medical director of the Borgess Women’s Heart Program and cardiologist with the Borgess Heart Center for Excellence, said research has shown that there is an increased risk of cardiovascular mortality associated with low vitamin D levels.

“No one fully understands why,” Moulla said, but she routinely screens patients for vitamin D levels.

“I consider (a low vitamin D level) a risk factor (for heart disease),” she said. “This is not yet a standard practice. Some doctors are not as aggressive. They should be.”

Karen Krusinga, a nurse practitioner at Borgess Medical Center, said research indicates that a deficiency of vitamin D may cause inflammation in the lining of the blood vessels. Inflammation makes plaque lining the blood vessels more likely to rupture and cause a heart attack.

Heart patients with symptoms such as fatigue, muscle pain and weakness might be deficient in vitamin D, Krusinga said.

A study in Salt Lake City, whose findings were presented in November at an American Heart Association conference, measured vitamin D levels in more than 27,000 healthy adults age 50 and older.

After about two years, those who had extremely low levels of the vitamin were twice as likely to develop heart failure than those with adequate amounts, 77 percent more likely to die, 78 percent more likely to have a stroke and 45 more likely to have coronary artery disease, the New York Times reported. Even those with moderate deficiencies were at greater risk.

The findings don’t prove that the low vitamin D levels cause heart disease so that’s the next thing for researchers to figure out, the Times said.

“If that does turn out to be the case, it would have pretty profound health implications,” Dr. Thomas Wang, an associate professor of medicine at Harvard, told the Times.

Wang did an earlier study that also showed a link between vitamin D deficiency and increased cardiovascular risk. He found the risk was particularly evident among those with high blood pressure, according to a ScienceDaily report.

 One of the best ways to boost your vitamin D levels is to get outside and expose your skin to sunlight, since sunlight stimulates the skin to synthesize vitamin D. But this can be difficult in the middle of a Michigan winter.

In most cases of vitamin D deficiency, supplements in the form of gel capsules or tables may be required.  But patients should always check with their physician before beginning any vitamin or supplement regimen, Moualla said.

Excessive amounts of vitamin D consumed in supplements can raise blood calcium levels and result in the formation of kidney stones.

Researchers are learning that vitamin D is crucial to many metabolic processes and could have an impact on other diseases as well.

Results of a new study by Montreal researchers, for example, show that vitamin D might help prevent and fight Crohn’s disease, a chronic inflammatory bowel disorder.

Dr. Ramon C. Raneses Jr., an interventional cardiologist at Alliance Cardiovascular at Bronson Methodist Hospital, said he finds it interesting that research links low levels of vitamin D with worse heart-health outcomes, but he said it’s not crystal clear what should be done in response to those findings.

“The real question is whether higher vitamin D will alter cardiac events,” he said.

He said that measuring vitamin D levels in heart patients is not a “huge priority,” but he believes the subject does warrant further study.

“It’s another case where they’re learning more and more about process and pathology,” he said, “but now we need to figure out what to do with it. It may be just another piece of the puzzle.”

Health Editor Margaret DeRitter contributed to this report.