A recent study (The Framingham Offspring Study) reported an increased risk for heart disease in people whose Vitamin D levels were low. People with high blood pressure were at an even higher risk than people with normal blood pressure.
The study suggests that Vitamin D blood levels less than 15 ng/ml may increase your risk for a heart attack, heart failure, and stroke. In the study even after adjusting for other common risk factors (high blood pressure, high cholesterol, diabetes) people with low Vitamin D levels were at a much higher risk compared to people with normal Vitamin D levels. Low Vitamin D levels are relatively common in the United States, especially among people who do not get a lot of sun exposure or in areas that do not get a lot of sunshine. Darker pigmented skin and the use of sunblock prevents the sun rays from being absorbed and decreases normal Vitamin D production in the body. Routine screening of Vitamin D levels is currently not recommended and you should discuss your individual risk with your health care provider. The American Heart Association recommends getting Vitamin D from food sources (milk, salmon, mackerel, sardines, fortified cereals) rather than taking supplements. Most people should consume between 800 and 1,000 IU of Vitamin D3 (cholecalciferol) daily.
Vitamin D Deficiency and Risk of Cardiovascular Disease