Vitamin D cuts risk of death from heart disease

Adults ages 65 and older may be less likely to die from heart disease if they take vitamin D supplements, according to new research.

The study by researchers at the University of Colorado, Denver and Massachusetts General Hospital (MGH) shows a link between insufficient vitamin D and higher risk of death from heart disease in people older than 65 years.

The researchers found that older adults with sufficient levels of vitamin D died from heart disease at lower rates than those with lower levels of the vitamin.

"It's likely that more than one-third of older adults now have vitamin D levels associated with higher risks of death and few have levels associated with optimum survival," said Dr. Adit Ginde, an assistant professor at the University of Colorado School of Medicine's Division of Emergency Medicine and lead author on the study.

"Given the aging population and the simplicity of increasing a person's level of vitamin D," he said, "a small improvement in death rates could have a substantial impact on public health."

Older adults are more likely than younger adults to be vitamin D deficient because they have less exposure to the sun due to more limited outdoor activities. They also have reduced ability to make vitamin D.

The study analyzed data from the Third National Health and Nutrition Examination Survey conducted by the National Center for Health Statistics.

Adit Ginde and colleagues analyzed vitamin D in blood samples of more than 3,400 men and women who participated in the survey.

They found those with low vitamin D levels were 3 times more likely to die from heart disease and 2.5 times more likely to die from any cause.

The research team has applied for funding from the National Institutes of Health to conduct a clinical trial of vitamin D supplementation in older adults to see if the vitamin can reduce the incidence of heart disease.

"Confirmation of these results in large randomized trials is critically important for advancing public health," said Dr. Carlos Camargo, of the MGH Department of Emergency Medicine, senior author of the study and an associate professor of medicine at Harvard Medical School.

Another study by the same team, published early this year in Archives of Internal Medicine, found vitamin D plays a significant role in boosting the immune system and warding off colds and flu.

"Vitamin D has health effects that go beyond strong bones," said Ginde. "It's likely that it makes a vital contribution to good health."

Dr. John Cannell, vitamin D expert and president of Vitamin D Council and his colleagues have demonstrated years ago that sufficient vitamin D can help prevent flu because the vitamin can promote production of antibacterial peptides.

Recent studies by other research teams also have found that vitamin D can help reduce heart attack risk.

Dr. Harald Dobnig, an internist and endocrinologist at the Medical University of Graz, Austria and colleagues published a study in the June 23, 2008 issue of the Archives of Internal Medicine saying that lower levels of vitamin D in the blood appears to increase risk of death from all causes and from cardiovascular diseases.

Dr. Dobnig and colleagues measured 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels in 3,258 patients aged 62 years who underwent coronary angiography testing between 1997 and 2000.  During the 7.7-year follow-up, 22.6 percent of participants died with 62.8 percent dying from cardiovascular causes.

Death rates from any cause and from the cardiovascular causes were higher in those with their blood 25-hydroxyvitamin D levels in the lower 50 percent and in the lowest one-fourth of 1,25-dihydroxyvitamin D levels, the study found.

Dr. Edward Giovannucci, one of the distinguished vitamin D experts in the world, of the Harvard School of Public Health and colleagues, published a June 2008 study in the Archives of Internal Medicine reporting that the risk for heart attack among men with hypovitaminosis D or vitamin D deficiency or having 15 nanograms per mL of blood or less was 2.42 times higher than for those with sufficient vitamin D or having 30 nanograms per mL of vitamin D.

The association between high levels of vitamin D and lower risk from dying from heart disease is unlikely the work of chance. Dr. Robert U. Simpson and colleagues from the University of Michigan reported in June 2008 that rats that were prone to heart failure and ate a high salt diet, but given calcitriol or 1,25 dihydroxyvitamin D3, the active form of vitamin D, had significantly lower levels of several key predictors of heart failure than rats on a high-salt diet, but untreated with the vitamin.

They also found that treated vitamin D, the rats had lower heart weight and the left ventricles of their hearts were smaller, meaning the animals were at lower risk of suffering heart failure.

A review published in the Dec. 9, 2008 issue of the Journal of the American College of Cardiology suggests that vitamin D deficiency is a risk factor for cardiovascular disease and patients at high heart risk should get screened and treated.

Dr. James H. O'Keefe, cardiologist and director of Preventive Cardiology at the Mid-America Heart Institute, Kansas City, MO., and colleagues said low levels of vitamin D activate the renin-angiostensin-aldosterone system and predispose people to hypertension and a stiffening and thickening of the heart and blood vessels.

The ACC says that up to half of U.S. adult men and women and 30 percent of children and teenagers suffer vitamin D deficiency, which is defined as a 25(OH)D level of <20ng/ml.

Dr. Cannell commented on the study in an email to foodconsumer.org that "vitamin D deficiency can easily be treated and the other risk factors for heart disease are often more difficult and always more expensive to treat."

He suggests that the optimal serum vitamin D level is between 50 and 70 ng/mL, which can be reached by taking 2000 to 5000 IU of the vitamin D each day.

Heart disease is the number one killer in the United States, according to the Centers for Disease Control and Prevention.

"In 2009, an estimated 785,000 Americans will have a new coronary attack, and about 470,000 will have a recurrent attack. About every 25 seconds, an American will have a coronary event, and about one every minute (about 520,000) will die from one," the CDC states.

By David Liu davidl at foodconsumer.org and edited by Sheilah Downey sheilah at foodconsumer dot org