Regular use of prenatal multivitamin supplements is not adequate to prevent vitamin D insufficiency, University of Pittsburgh researchers report in the current issue of the Journal of Nutrition, the publication of the American Society for Nutrition. A condition linked to rickets and other musculoskeletal and health complications, vitamin D insufficiency was found to be widespread among women during pregnancy, particularly in the northern latitudes.
“In our study, more than 80 percent of African-American women and nearly half of white women tested at delivery had levels of vitamin D that were too low, even though more than 90 percent of them used prenatal vitamins during pregnancy,” said Lisa Bodnar, Ph.D., M.P.H., R.D., assistant professor of epidemiology at the University of Pittsburgh Graduate School of Public Health (GSPH) and lead author of the study.
“The numbers also were striking for their newborns — 92.4 percent of African-American babies and 66.1 percent of white infants were found to have insufficient vitamin D at birth.”A vitamin closely associated with bone health, vitamin D deficiency early in life is associated with rickets — a disorder characterized by soft bones as well as increased risk for type 1 diabetes, asthma and schizophrenia.
“A newborn’s vitamin D stores are completely reliant on vitamin D from the mother,” observed Dr. Bodnar, who also is an assistant investigator at the university-affiliated Magee-Womens Research Institute (MWRI). “Not surprisingly, poor maternal vitamin D status during pregnancy is a major risk factor for infant rickets, which again is becoming a major health problem.”“This study is among the largest to examine these questions in this at-risk population,” Marjorie L. McCullough, Sc.D., senior epidemiologist at the American Cancer Society, wrote in an accompanying editorial. “By the end of pregnancy, 90 percent of all women were taking prenatal vitamins and yet deficiency was still common.”Vitamin D is found naturally in fatty fish but few other foods.
Primary dietary sources include fortified foods such as milk and some ready-to-eat cereals and vitamin supplements. Sun exposure for skin synthesis of vitamin D also remains critical.“Our study shows that current vitamin D dietary intake recommendations are not enough to meet the demands of pregnancy,” Dr. Bodnar said. “Improving vitamin D status has tremendous capacity to benefit public health.”
