A new study shows an association between low vitamin D levels and risk factors for cardiovascular disease "in a nationally representative sample."

Dr. Keith Norris, at Drew University School of Medicine in Los Angeles, and colleagues analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III), conducted between 1988 and 1994.

They evaluated blood levels of vitamin D and the risk of heart-related disease in 7,186 men and 7,902 women.

Average vitamin D levels were lower in women, older individuals, racial and ethnic minorities, obese people and those with hypertension or diabetes, the researcher report in the Archives of Internal Medicine.

Compared to people with the highest vitamin D levels, those with the lowest levels were more likely to have high blood pressure, diabetes, and obesity -- all risk factors for heart disease.

Norris said that this evidence of the link between heart disease and vitamin D "reinforces the emerging evidence that suggests higher levels of vitamin D may be helpful to reduce the risk of cardiovascular disease."

In terms of taking a vitamin D supplement, "present dose recommendations range from 800 IU to 1,200 IU daily," he noted. However, he thinks 2000 IU per day is more likely to achieve adequate blood levels of vitamin D for prevention of cardiovascular disease. "There appears to be good safety at doses of 2000-3000 IU per day."

He pointed out that it has been known for a long time that vitamin D helps to make strong bones, but there is now "convincing evidence" that it has several beneficial effects on cardiovascular health.

"The potential implications from a public health and healthcare cost perspective are tremendous, even if vitamin D only impacts 5 percent to10 percent of heart health," Norris concluded.