Researchers from the University of Rochester, in the United States, have discovered that low levels of vitamin D presented by black people could be a powerful factor that contributes to the emergence of racial differences that exist with respect to hypertension, a problem more common and often more deadly among the black population than among the white race.

These discoveries, published in the online edition of Journal of General Internal Medicine, agree with the theory, which increasingly has more evidence, that low levels of vitamin D are associated with hypertension and that Black people produce less vitamin D.   

The team of the professor of Family Medicine of the URMC, Kevin Fiscella, leader of this work, analyzed the data from the National Health Survey and Nutrition Examination 2001-2006, including in the sample 2,000 black patients and 5,100 non-Hispanic whites , of 20 years or more. The researchers compared the mean systolic blood pressure and vitamin D levels of the study participants.

They found that 61% of black patients, compared to 11% of whites, had vitamin D levels at the lowest levels, while only 2% of black patients compared to 25% of whites had levels of vitamin D at the highest levels.

"This study confirms that vitamin D represents a piece of the complex puzzle that makes up race and blood pressure," says Fiscella, who notes that, "given that the differences between black and white with respect to blood pressure are hundreds of deaths from heart disease and stroke among black people, we believe that simple interventions-such as taking vitamin D supplements-could have a positive impact on racial differences. "

However, Fiscella acknowledges that his study has some limitations and that vitamin D does not fully explain the racial differences regarding hypertension. Therefore, he says, "it is likely that other factors beyond vitamin D, such as psychological stress, adherence to treatment and discrimination, could contribute to the existence of this disparity," and warns that "more studies will be necessary. using more refined measures than skin color, to clarify the complex relationship between skin type, stress, vitamin D and hypertension.

The importance of vitamin D

Most vitamin D is produced by the skin in response to sunlight and metabolized in the liver, where it is converted to 25 hydroxyvitamin D or 25 (OH) D, which is the way in which vitamin status is determined D of a person through a blood test. The deficiency is usually defined as less than 20 nanograms per millimeter (Ng / ml); Having less than 15 Ng / ml is inadequate to maintain healthy bones and normal calcium metabolism.

Many people around the world have low concentrations of vitamin D. Certain genetic factors common to black people, such as the dark color of the skin, reduce the synthesis of vitamin D. In addition, the higher incidence of lactose intolerance than present the black people, who can eliminate milk enriched with vitamin D from the diet, contributes to a lower dietary intake, than previous research had already shown.


Vitamin D Deficiency Not Tied to Fatal Strokes in Blacks (November 2019).