Black Women, Newborns in Pittsburgh Area Have Greater Risk for Vitamin D Deficiency Than White Women, Study Says

Pregnant black women and their infants living in the Pittsburgh, Pa., area are more likely than white women to have vitamin D insufficiency, despite taking multivitamin and prenatal supplements regularly, according to research published in the current issue of the Journal of Nutrition, the Pittsburgh Post-Gazette reports. For the report, lead researcher Lisa Bodnar, assistant professor of epidemiology at the University of Pittsburgh Graduate School of Public Health and an investigator at the Magee-Womens Research Institute, and colleagues analyzed data of 200 black women and 200 white women from the Pittsburgh area. The women were randomly selected from more than 2,200 pregnant women enrolled in a study at Magee-Womens between 1997 and 2001. The study found that more than 80% of black women and nearly 50% of white women after giving birth had vitamin D levels that were too low, Bodnar said. Almost 90% of the women took prenatal vitamins. Among all women, vitamin D levels were highest in the summer and lowest in the winter and spring, though the seasonal differences in vitamin D levels were smaller for black women and their infants, the Post-Gazette reports. Of black infants, 92.4% had insufficient vitamin D levels at birth, compared with 66.1% of white infants. Infants born to women with low vitamin D levels could be at greater risk for rickets and other health problems, including type 1 diabetes and asthma. According to Bodnar, individuals with darker skin have to be exposed to the sun for longer periods of time than other people to make vitamin D. In addition, blacks are less likely than whites to take vitamin supplements and eat foods fortified with vitamin D. Bodnar suggested increasing the vitamin D levels in prenatal vitamins from about 400 international units to 1,000 units. The study "illuminates the danger of assuming that prenatal vitamins in their present form are ensuring vitamin D sufficiency in pregnant women and their newborns," Marjorie McCullough, a senior epidemiologist for the American Cancer Society, said in an editorial accompanying the study. She called for more research into determining how much vitamin D various racial and ethnic groups should have, but she added, "[W]e do have enough evidence to show that current practices are not serving at-risk groups" (Fahy, Pittsburgh Post-Gazette, 2/28).
An abstract of the study is available online.