Study finds link between vitamin D deficiency and increased heart disease risk

SALT LAKE CITY - Recent studies have found that vitamin D deficiency is linked to more serious health risks such as coronary artery disease, heart attacks and strokes, in addition to weakened bones.

 

Researchers at the Intermountain Medical Center Heart Institute here have found that patients are fine from a heart standpoint, and may need no further treatment, if their vitamin D level is anywhere above 15 nanograms per milliliter.

 

“Although vitamin D levels above 30 were traditionally considered to be normal, more recently, some researchers have proposed that anything above 15 was a safe level. But the numbers hadn’t been backed up with research until now,” said Brent Muhlestein, co-director of cardiovascular research at the Intermountain Medical Center Heart Institute, and lead researcher of the study.

 

“Even if any level above 15 is safe, one out of 10 people still have vitamin D levels lower than that. This equates to a very large percentage of our population,” he said.

 

Muhlestein and his team have studied the effects of vitamin D on the heart for several years, looking at smaller numbers of patients. In this study, thanks to Intermountain Healthcare’s vast clinical database, they were able to evaluate the impact of vitamin D levels on more than 230,000 patients.

 

The 230,000 patients were split up into four groups (those with vitamin D levels of less than  15 ng/ml, levels of between 15-29, levels of between 30-44 and levels greater than or equal to 45) and were followed for the next three years by researchers who looked for major adverse cardiac events, including death, coronary artery disease, heart attacks, stroke and incidents of heart or kidney failure.

 

Muhlestein found that for the 9% of patients in the less than 15 group, their risk of cardiovascular events increased by 35% compared to the other three groups, and the risks faced by the other three groups weren’t very different from each other.

 

“This study sheds new light and direction on which patients might best benefit from taking vitamin D supplements,” Muhlestein said. “Even though there’s a possibility that patients may benefit in some way from achieving higher blood levels of vitamin D, this new information tells us the greatest benefit to the heart will likely occur among patients whose vitamin D level is below 15 ng/ml.”

 

Going forward, Muhlestein hopes to take these findings and perform a randomized trial with patients whose levels are below 15. The idea is to randomly separate them into groups and provide supplements for one but not the other to see what the long-term benefits for combatting heart problems really are.

 

“As we continue to study vitamin D and the heart, we hope to ultimately gain enough information so we can inform all patients specifically what they should do to reduce their cardiac risk as much as possible,” he said.