Arab-American women living in southeast Detroit whose conservative dress limits their exposure to sun should be taking a vitamin D supplement to boost their dangerously low serum levels, according to a study published by Henry Ford Hospital researchers.
Researchers found that all 87 women involved in a small study showed vitamin D levels averaging 8.5 ng/mL (nanograms per milliliter) for those who wore western dress to 4 ng/mL for those who wore the hijab, modest dress with a headscarf. A healthy vitamin D level is 30 ng/mL or higher.
Also, the women consumed little dietary sources of vitamin D. Forty-seven women reported drinking any milk on a weekly basis, but the amount they consume isn't significant enough to boost their vitamin D levels, researchers say.
The study is published in the January/February issue of Endocrine Practice . It is believed to be the largest study on the prevalence of vitamin D deficiency in one of the largest concentrations of Arab Americans in southeast Michigan.
Raymond Hobbs, M.D., a Henry Ford Internal Medicine physician and lead author of the study, described the vitamin D deficiency in the women as "much greater than we would have thought."
"When people live where the weather is colder and they are more covered with clothing, they depend on their diet for their vitamin D," Dr. Hobbs says. "Unfortunately, most food with the exception of oily fish and vitamin D fortified milk has very little vitamin D. The women in our study drank very little milk, fortified orange juice and had decreased sun exposure because of their dress."
Low levels of vitamin D are linked to increased risk of cancer, diabetes and Crohn's disease, Dr. Hobbs says. Vitamin D is needed to maintain normal blood levels of calcium and phosphorus. It also helps in the absorption of calcium, helping to form and maintain strong bones.
"Our findings are consistent with those of similar studies in other parts of the world and underscore the point that there are pockets of individuals who are at risk for culturally mediated health problems," Dr. Hobbs says. "We need to raise their awareness of this deficiency and to offer them options for increasing their vitamin D levels. A vitamin D supplement is a start."
More than 490,000 Arab Americans reside in southeast Michigan, the largest population anywhere outside the Middle East. For the study, researchers looked at Arab-American women in the city of Dearborn, a southeast Detroit suburb in which Arab Americans comprise one third of the 100,000 population.