The Connection Between Vitamin D and Heart Disease

Lisa Nelson RD #9: Is there a connection between vitamin D and heart disease?  What level vitamin D should individuals maintain to prevent heart problems?

Dr. Shelby-Lane: It is a known and documented fact that too little Vitamin D puts the heart at risk.  Yet many patients are not routinely tested, and if so, they do not take the proper steps to reach optimal Vitamin D levels between 50 to 100 ng/dL.  Most lab tests give 30 as a low normal, yet this is not optimal.  This can by done by diet, sun exposure (in most cases) or adequate supplementation.  But most of all, people are not tested.   Research suggests Vitamin D deficiency may be an unrecognized heart disease risk factor.

Researchers say a growing body of evidence suggests that vitamin D deficiency increases the risk of heart disease and is linked to other, well-known heart disease risk factors such as high blood pressure, obesity, and diabetes.

For example, several large studies have shown that people with low vitamin D levels were twice as likely to have a heart attack, stroke, or other heart-related event during follow-up, compared with those with higher vitamin D levels.

"Vitamin D deficiency is an unrecognized, emerging cardiovascular risk factor, which should be screened for and treated," says researcher James H. O'Keefe, MD, director of preventive cardiology at the Mid America Heart Institute in Kansas City, Mo., in a news release. "Vitamin D is easy to assess and supplementation is simple, safe and inexpensive."

Most of the body's vitamin D requirements are met by the skin in response to sun exposure. Other less potent sources of vitamin D include foods such as salmon, sardines, cod liver oil, and vitamin D-fortified foods like milk and some cereals. Vitamin D can also be obtained through supplements.

Vitamin D deficiency is on the rise.   Vitamin D deficiency is traditionally associated with bone and muscle weakness, but in recent years a number of studies have shown that low levels of the vitamin may predispose the body to high blood pressure, congestive heart failure, and chronic blood vessel inflammation (associated with hardening of the arteries). It also alters hormone levels to increase insulin resistance, which raises the risk of diabetes.

In a review article published in the Journal of the American College of Cardiology, researchers surveyed recent studies on the link between vitamin D deficiency and heart disease to come up with practical advice on screening and treatment.

They concluded that vitamin D deficiency is much more common than previously thought, affecting up to half of adults and apparently healthy children in the U.S.

Researchers say higher rates of vitamin D deficiency may be due in part to people spending more time indoors and efforts to minimize sun exposure through the use of sunscreens. Sunscreen with a sun protection factor (SPF) of 15 blocks approximately 99% of vitamin D synthesis by the skin.