A team of University researchers received a $2.2 million grant to study how varying doses of vitamin D affect overall bone health in children. Researchers currently have a limited understanding of the effects of vitamin D in children and younger adults.

The Eunice Kennedy Shriver National Institute of Child Health and Human Development – one of 27 national institutes – awarded the grant to leading researcher Richard Lewis, a professor of food and nutrition at the University’s Bone and Body Composition Laboratory.

“Overall, we’ve been looking at how vitamin D levels decrease when children reach puberty and mature into adults,” Lewis said. “We’re trying to understand how vitamin D may affect bone health and skeletal structures in children.”

The project follows research findings that 60 percent of children and adolescents lack sufficient levels of vitamin D – which can be found in foods such as orange juice, milk and mushrooms.

Vitamin D, converted to active forms in the body, can be obtained by consuming certain foods, taking supplements or from ultraviolet rays in sunlight. In adults, researchers credit vitamin D for increased calcium absorption in the digestive system and for maintaining normal bone mineralization, among other things.

Recommended vitamin D doses for adults have been established, but supplemental recommendations for children have not.

Lewis said the project will also look at the role race and seasons have on vitamin D levels, as skin color affects vitamin D absorption and synthesis.

Contributing to the project will be University post-doc research associate Emma Laing, associate research scientist Dorothy Hausman, distinguished professor at Purdue University Connie Weaver, Michael Kimlin from Queensland University of Technology in Australia and graduate students.

Dan Hall, associate head of the University’s Department of Statistics, modeled the study and will analyze the data.

Half of the study will be conducted at the University and the other half will be at Purdue University in Indiana. During a 12-week intervention period, 320 children from the ages of nine to 13 will be given different doses of vitamin D supplements.

Children involved in the study at the University will begin in October and end in December. One group will receive no vitamin D and will serve as the control.

The other four cohorts will receive doses between 400 and 5,000 international units of vitamin D throughout five trips to the lab. Researchers will study active levels of vitamin D in the bloodstream to determine how each child absorbed and converted the supplement.

Meanwhile, the children’s parents will log each child’s diet, sun exposure, physical activity and overall health.

Hall, who often collaborates with other researchers at the University, said the presence of a control group contributes to the study’s strong experimental design. He also commented on the evolving application of statistics.

“The discipline stands on it’s own, but it’s becoming a more collaborative field these days,” Hall said. “This is very much the case at UGA.”

Ashley Ferira, a third-year doctoral student at the lab, said she has enjoyed conducting clinical research on campus and looks forward to helping in follow-up studies to examine the relationship between vitamin D and Type 2 Diabetes.

“I’m lucky enough to have the opportunity to come back this year for this project,” said Maria Breen, a graduate student finishing her master’s degree.