May 8, 2007
Contact: Kaylyn Kendall Dines
Phone: (973) 972-3000
UMDNJ Researchers Say Age, Race and Season
are Factors in Vitamin D Deficiency and Lead Poisoning
NEWARK — Outcomes of a study conducted by researchers at the University of Medicine and Dentistry of New Jersey demonstrate that the season of the year, age and race are factors that affect blood lead levels and vitamin D deficiency in children who live in urban areas. Findings from this study are published in a recent edition of Environmental Health Perspectives.
In the article, “Elevated Blood Lead Concentrations and Vitamin D Deficiency in Winter and Summer in Young Urban Children,” researchers at the UMDNJ-New Jersey Medical School found that young African-American children were more likely to be deficient in vitamin D and have higher blood lead levels when compared with their Hispanic counterparts. In addition, increases in blood lead during the summer were associated with increases in blood vitamin D levels in the four to 8-year-old children studied.
“We collected blood samples from 142 African-American and Hispanic children in the winter and summer to study the seasonal increase in blood lead levels and its relationships to Vitamin D nutrition, age, and race,” said Francis Kemp, a project coordinator in the Department of Preventive Medicine and Community Health at the UMDNJ-New Jersey Medical School. “Unfortunately, about 25 percent of the four to 8-year old African American children were deficient in Vitamin D. In contrast, none of the Hispanic children in the same age group were deficient in Vitamin D.”
The study confirms prior research that shows blood lead concentrations are higher in the summer than in winter. Environmental factors such as more exposure of children to lead in dust in the summer are one reason for this seasonal effect. However the relationships of blood lead to sunlight-induced vitamin D synthesis has not been adequately investigated. The authors studied vitamin D status because it is influenced by diet, sunlight exposure, age, skin pigmentation, other factors, and may increase gastrointestinal lead absorption or release of lead stored in bones into the bloodstream.
The cohort, 91 African American and 51 Hispanic children, were participants enrolled in the Women, Infants, and Children (WIC) program at UMDNJ. The researchers found that in the summer more than 20 percent of the African American children who were between ages one and three had elevated blood lead concentrations compared to about 10 percent with high levels during the winter. In contrast, African American children who were between ages four and eight were more likely to have vitamin D deficiency in the winter than African American children ages one to three. Season and age had a much smaller impact on blood lead levels and Vitamin D concentrations in Hispanic children in those age groups.
Education, awareness and professional removal of lead-based paint are key factors in preventing exposures to lead, a neurotoxin that is known to result in developmental impairment.
“We were surprised by the striking differences between Hispanic and African American children in the prevalence of vitamin D deficiency and elevated blood lead levels because all of the children were from the similar socio-economic backgrounds,” said Dr. John Bogden, a professor in the Department of Preventive Medicine and Community Health at the UMDNJ-New Jersey Medical School. “Additional research on the causes of the differences in the prevalence of vitamin D deficiency and elevated blood levels in African-American and Hispanic children is needed. Although we want to reduce the prevalence of vitamin D deficiency in young urban children, we will need to be careful to do so without increasing their blood lead concentrations.”
In addition to Mr. Kemp and Dr. Bogden, the co-authors of the study are: Drs. Prasad Neti, Roger Howell, Peter Wenger, and Donald Louria. The researchers are members of the Department of Preventive Medicine and Community Health, and the Department of Radiology at the UMDNJ-New Jersey Medical School. This research was supported by the Institute for the Elimination for Health Disparities at the UMDNJ-School of Public Health and the Healthcare Foundation of New Jersey.
UMDNJ is the nation’s largest free-standing public health sciences university with more than 5,700 students attending the state’s three medical schools, its only dental school, a graduate school of biomedical sciences, a school of health related professions, a school of nursing and a school of public health on five campuses. Annually, there are more than two million patient visits at UMDNJ facilities and faculty practices at campuses in Newark, New Brunswick/Piscataway, Scotch Plains, Camden and Stratford. UMDNJ operates University Hospital a Level I Trauma Center in Newark, and University Behavioral HealthCare, a statewide mental health and addiction services network.