Low vitamin D levels tied to higher blood pressure

NEW YORK (Reuters Health) - As blood levels of vitamin D drop, blood pressure increases, according to findings from the Third National Health and Nutrition Examination Survey (NHANES III).

The current analysis from NHANES III, which was conducted between 1988 and 1994, involved 12,644 adults in the U.S. aged 20 years and older who had blood pressures recorded and vitamin D levels measured.

As reported in the American Journal of Hypertension, Dr. Robert Scragg of the University of Auckland, New Zealand, and colleagues found the lowest vitamin D levels in non-Hispanic blacks, followed by Mexican Americans, and then non-Hispanic whites.

After accounting for age, gender, ethnicity, and physical activity, patients with the lowest vitamin D levels had blood pressures that were slightly higher than those with the highest levels. This relationship was strongest in subjects who were 50 years of age and older.

Differences in vitamin D levels explained in, large part, why high blood pressure was more common in non-Hispanic blacks than in whites, the authors state.

They note that "vitamin D levels can easily, and cheaply, be increased by a modest increase in sun exposure or vitamin D supplementation," but they caution that "first it needs to be confirmed by large, well-designed intervention studies."

SOURCE: American Journal of Hypertension, July 2007.