Low blood concentrations of vitamin D may be
associated with higher blood pressure in whites, indicating a risk of
developing hypertension, or high blood that requires medical treatment,
researchers report. However, this relationship was not noted among
blacks.

"Though easily corrected by taking a vitamin D
supplement or having causal sunlight exposure, vitamin D insufficiency
is highly prevalent in the United States," Dr. Vin Tangpricha told
Reuters Health.

Tangpricha and colleagues, all from Emory University School of
Medicine in Atlanta, looked at the association between systolic blood
pressure - the top number of the blood pressure reading representing
the pressure during contraction of the heart muscle -- and vitamin D
levels among 7,699 adults without high blood pressure. Forty-seven
percent were male, 61 percent were white, and 39 percent were black.

The study population had participated in the third National Health
and Examination Survey conducted from 1988 to 1994, which provides the
most recent nationally representative data on vitamin D concentrations
among U.S. adults, the investigators report in the American Journal of
Clinical Nutrition.

Overall, 61 percent of whites and 92 percent of blacks had vitamin D
deficiency. Most (63 percent) of the participants were 18 to 49 years
old, and 37 percent were 50 years or older when systolic blood pressure
and vitamin D measurements were obtained.

The investigators found that white participants with sufficient
vitamin D levels had a 20-percent lower rise in age-associated systolic
blood pressure compared with those with insufficient vitamin D levels.
This relationship was not statistically significant in blacks.

"This paper does not provide direct evidence that vitamin D supplementation will lower blood pressure," Tangpricha cautions.

He and colleagues suggest that further research examine in more
detail how vitamin D status affects blood pressure in black and white
populations. Improved methods for detecting vitamin D deficiency are
also necessary, they conclude.