Charles Stephensen found low levels of vitamin D
in young African-Americans. Click the image for more information about
Young African-Americans' Low Vitamin D Levels
Reported By Marcia Wood May
Low vitamin D levels among young African-Americans participating in a
recent study were more common than in several previous investigations,
university and Agricultural Research Service (ARS) nutrition experts have found.
The vitamin is essential for strong bones and a robust immune system,
according to the study's lead author, immunologist
B. Stephensen. He works at the ARS
Human Nutrition Research Center, located at the
University of California,
Stephensen and his co-investigators have reported their findings in
the current issue of the American Journal of
The scientists based their conclusion on levels of a form of vitamin D
in the blood (plasma) of 359 volunteers, aged 15 to 19, tested at sites in 14
American cities. Volunteers were predominantly female African-Americans.
Researchers found that 87 percent of the volunteers had an
insufficient amount of what's known as 25-hydroxyvitamin D in their plasma.
Though some earlier studies had suggested that more Americans than was
previously estimated may be short of vitamin D, the 87 percent figure was
unexpectedly high, according to Stephensen.
People who have levels of 25-hydroxyvitamin D at or below 37.5
nanomoles per liter of blood are considered vitamin D-deficient.
Good sources of the nutrient include vitamin D-fortified milk, fatty
fish and sunshine, which a natural chemical in skin can convert to a form of
the nutrient called previtamin D3.
The study was funded in part by ARSthe U.S. Department of Agriculture's chief
scientific research agencyand by the National
Institutes of Health, part of the U.S.
Department of Health and Human Services.
The study volunteers represented a majority of the participants in the
federally funded REACH investigation, short for "Reaching for Excellence in
Stephensen worked on the study with colleagues from the
University of Southern California at Los
Angeles; Iowa State University at
Ames; the University of Pennsylvania at
Philadelphia, and the University of Alabama at