The results of a study presented on November 16, 2009 at the American Heart Association's Scientific Conference in Orlando, Florida, confirmed a strong association between the presence of reduced vitamin D levels and a greater risk of coronary artery disease, stroke, heart failure and dying over follow-up in men and women 50 years of age and older.
Brent Muhlestein, MD and his colleagues at Intermountain Medical Center in Salt Lake City followed 27,686 subjects with no history of heart disease for an average of 1.2 years. Serum 25-hydroxyvitamin D levels obtained during routine clinical care were classified as normal at over 30 nanograms per milliliter (ng/mL), low at between 15 to 30 ng/mL or very low at less than 15 ng/mL.
Over the follow-up period, 2,614 participants developed coronary artery disease, 1,742 developed heart failure, 314 experienced a stroke and 1,193 deaths occurred. Those with very low vitamin D levels were 45 percent likelier to develop heart disease, twice as likely to develop heart failure, 78 percent more likely to experience a stroke,and 77 percent likelier to die than those with normal levels. Subjects whose vitamin D levels were classified as "low" as opposed to "very low" also had greater risks of these conditions, however, the increase compared to those with normal levels was not as great as the very low group.
"This was a unique study because the association between Vitamin D deficiency and cardiovascular disease has not been well-established," commented Dr Muhlestein, who is the director of cardiovascular research of Intermountain Medical Center's Heart Institute. "Its conclusions about how we can prevent disease and provide treatment may ultimately help us save more lives."
"Utah's population gave us a unique pool of patients whose health histories are different than patients in previous studies," he remarked. "For example, because of Utah's low use of tobacco and alcohol, we were able to narrow the focus of the study to the effects of vitamin D on the cardiovascular system."
"We concluded that among patients 50 years of age or older, even a moderate deficiency of Vitamin D levels was associated with developing coronary artery disease, heart failure, stroke, and death," noted coauthor Heidi May, PhD, MS, who is an epidemiologist with the Intermountain Medical Center research team. "This is important because vitamin D deficiency is easily treated. If increasing levels of vitamin D can decrease some risk associated with these cardiovascular diseases, it could have a significant public health impact. When you consider that cardiovascular disease is the leading cause of death in America, you understand how this research can help improve the length and quality of people's lives."
"We believe the findings are important enough to now justify randomized treatment trials of supplementation in patients with Vitamin D deficiency to determine for sure whether it can reduce the risk of heart disease," Dr Muhlestein added.