Researchers report that news in today's advance online edition of Circulation.
Data came from 1,739 adults enrolled in the Framingham Offspring Study, a long-term health study based in Framingham, Mass.
Harvard Medical School's Thomas Wang, MD, and colleagues tracked participants with no history of heart problems who were 59 years old, on average.
By the end of the study period, 120 participants had had a cardiovascular event, such as a heart attack, stroke, chest pain, heart failure, and peripheral claudication (pain in the legs caused by circulation problems).
People with vitamin D deficiency and hypertension were about twice as likely as people without hypertension and vitamin D deficiency to have a cardiovascular event during the study. Vitamin D deficiency wasn't linked to cardiovascular problems in people who don't have hypertension.
Other factors, including physical activity, age, gender, and type 2 diabetes, didn't explain the results. But Wang's team can't rule out other influences.
Wang's study was purely observational; participants weren't told to take vitamin D or to spend more time in the sun so that their bodies could make more vitamin D. The researchers call for other studies to see if treating vitamin D deficiency lowers heart risks.