Low Vitamin D Levels Found in Otherwise Healthy Children

10/31/2007

Many children who are otherwise healthy have low levels of vitamin D, according to a study by Children's Hospital investigators.

Vitamin D is vital for musculoskeletal health as well as immune function, and deficiency in the vitamin is an underacknowledged problem. The main dietary source of vitamin D is fortified milk, but exposure to sunshine also increases blood levels of vitamin D. Severe shortages of vitamin D can cause muscle weakness, defective bone mineralization and rickets. Low blood levels of the vitamin may be a factor of hypertension, cancer, multiple sclerosis, and type 1 diabetes.

A study in the American Journal of Clinical Nutrition measured blood levels of vitamin D, dietary and supplemental vitamin D intake and body mass index of 382 healthy children between 6- and 21 years of age in the northeastern U.S.

Findings revealed that more than half the children had low blood levels of vitamin D, 55 percent had inadequate blood levels and 68 percent had low blood levels in winter. Children's Hospital researchers found that African-American children, children over the age of 9 and children with low amounts of vitamin D in their diets were most likely to have low blood levels of vitamin D. Though low levels of the vitamin can be detrimental to health, further study will determine what can be considered appropriate levels of vitamin D in children.

"The best indicator of a person's vitamin D status is the blood level of a vitamin D compound called 25-hydroxyvitamin D," says Babette Zemel, Ph.D., a nutritional anthropologist at Children's Hospital and the primary investigator of this study. She adds that further studies are needed to determine the appropriate blood levels of vitamin D in children and the optimal dietary intake of the vitamin.

Grants from the Joseph Stokes Jr. Research Institute, National Institutes of Health and several private sources supported this study. Dr. Zemel's Hospital co-authors include Mary Leonard, M.D., Division of Nephrology, and Virginia Stallings, M.D., Division of Gastroenterology, Hepatology and Nutrition.