Researchers found that all 87 women involved in a small study showed vitamin D levels averaging 8.5 ng/mL (nanograms per millilitre) for those who wore western dress to four 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 is not significant enough to boost their vitamin D levels, researchers say. Raymond Hobbs, 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," 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, 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.
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. The researchers recruited women who attended an ethnic supermarket in Dearborn during the course of two Saturdays in April 2007 to search for correlations with dress, diet, use of vitamin D-fortified foods and vitamin supplements.
They were interviewed to assess dress, medical history, medication use, clinical symptoms associated with vitamin D deficiency, consumption of fortified milk or fortified orange juice and vitamin supplements. Blood samples also were taken onsite and analysed for levels of vitamin D and parathyroid hormone and other minerals.
MEDICA.de; Source: Henry Ford Health System