Vitamin D Deficiency Linked To Increased Cardiovascular Disease

Vitamin pillsVitamin D deficiency may be associated with more than a two-fold increase in coronary heart disease risk according to a recent study funded by the American Heart Association.

The researchers looked at data from 1,739 offspring of the Framingham Heart Study with an average age of 59 years. The participants had their blood levels of Vitamin D recorded in 1996, as well as their blood pressures, current smoking habits, diabetes status, cholesterol levels, and physical activity levels. The participants were free of heart disease and other cardiovascular problems at the beginning of the study.

After an average follow up period of 5.4 years, 120 (6.9%) of the participants had developed some form of cardiovascular disease, with 65 of the patients suffering from coronary heart disease, 19 suffering from heart failure and 28 suffering cerebrovascular events such as strokes.

The researchers found that after adjusting for age and sex, the risk of developing cardiovascular disease was 2.04 times higher in the group that had vitamin D levels less than 15ng/mL compared to those with vitamin D levels greater than 15ng/mL. Furthermore, the group with vitamin D levels less than <10ng/mL had 2.63 times greater risk of cardiovascular disease than the group with vitamin D levels greater than 15ng/mL.

After adjusting the results for other cardiovascular disease risk factors such as blood pressure, diabetes status, cholesterol levels, and BMI, the relative risks of cardiovascular disease dropped slightly to 1.62 times and 1.80 times greater for the <15ng/mL and the <10ng/mL groups respectively.

The researchers also found that in participants with hypertension, vitamin D deficiency increased cardiovascular risks by an even greater amount while in individuals without hypertension, vitamin D deficiency led to only a small, non-significant increase in cardiovascular disease risk.

The research authors concluded that: “These prospective, community-based data suggest that vitamin D deficiency is associated with increased cardiovascular risk, above and beyond established cardiovascular risk factors. The higher risk associated with vitamin D deficiency was particularly evident among individuals with hypertension.”

The study also found that vitamin D levels across the participants were quite low with less than 10% of the participants having levels of vitamin D in the blood greater than 30ng/mL which is considered optimal. Vitamin D deficiency is relatively common, particularly in the winter months and in people living in very high or very low latitudes were sunlight exposure is insufficient to allow the body to synthesize vitamin D. In these people vitamin D must be consumed through dietary sources such as fortified milk and cereals, fatty fish and fish oils, mushrooms, and eggs.

The researchers added that: “Low levels of vitamin D are highly prevalent in the United States, especially in areas without much sunshine, 20 to 30 percent of the population in many areas has moderate to severe vitamin D deficiency.”

Vitamin supplementation is another way to increase vitamin D levels however experts urge caution as in people without a vitamin D deficiency, additional vitamin D will not necessarily improve cardiovascular health and in some recent studies, high doses of some vitamins have actually been shown to increase mortality.

The research appears in the American Heart Association’s journal, Circulation.