A University of Georgia nutrition researcher has received a $2.2 million grant to explore the role vitamin D plays in children’s health and the appropriate dose children should take to maintain healthy levels.

The grant, awarded by the National Institutes of Health Eunice Kennedy Shriver National Institute of Child Health and Human Development, comes on the heels of an August report in the journal Pediatrics, which showed 60% of children and adolescents had insufficient levels of vitamin D.

“The findings in Pediatrics confirmed what we have been seeing in our research,” said Rick Lewis, professor of foods and nutrition in the UGA College of Family and Consumer Sciences. “In prior research we’ve conducted with female children and adolescents over the course of seven years, we’ve consistently found that they have lower levels of vitamin D than are recommended and that those levels drop as they grow older.”

Although vitamin D has long been considered essential for bone health in individuals of all ages, research on the vitamin has primarily focused on its impact in older adults, he added. Research on older adults also has shown links between vitamin D deficiencies and cancer, diabetes and obesity.

During the two-year study, Mr. Lewis and fellow UGA researchers Emma Laing and Dorothy Hausman will team with researchers at Purdue University in providing varying doses of vitamin D supplements to boys and girls ranging in age from 9-13, ages deemed as being on the cusp of rapid growth periods. The group also will be evenly divided racially because research has consistently shown that African-American children tend to have lower levels of vitamin D than white children.

One goal of the new study is to determine if African-American children and white children respond differently to oral supplements of vitamin D. Another collaborator on the project is Michael Kimlin of Queensland University of Technology in Australia, who will help in collecting sun exposure data for the study.

Researchers will look at several biochemical measures of bone health, including calcium absorption, to determine the appropriate dose of vitamin D supplements children need to ensure that they grow up with strong, healthy bones.

Although it’s recommended that adults maintain a level of vitamin D in their blood stream that equates to 80 nanomoles per liter, the needs of children haven’t been fully established. Currently, the Food and Nutrition Board at the Institute of Medicine recommends children under the age of 13 receive 200 IU daily, while the American Academy of Pediatrics recommends children receive 400 IU.

The sun has always been considered a primary source of vitamin D because it causes the vitamin to be synthesized in the skin. However, for those with darker skin, those living in areas where the sun doesn’t shine as frequently, and those who either wear sunblock or don’t get out in the sun for other reasons, supplements have long been considered important to ensuring individuals have enough vitamin D.