The results of a study of over 2,000 teens aged 16 to 19 presented at the American Thoracic Society International Conference on May 22, 2006 found that those whose intake of vitamin D was low had poorer lung function than those whose diets met the recommended amount. The vitamin is found in dairy products, egg yolks, saltwater fish, and in many calcium and multivitamin supplements. The recommended daily allowance of vitamin D for this age group is 200 international units, which is less than what many authorities consider optimal. Jane Burns, ScD, who is a research fellow at the Department of Environmental Health at the Harvard University School of Public Health in Boston, decided to study adolescents because of their notoriously poor eating habits. Dr Burns and her colleagues found that 35 percent of the 2,112 adolescents studied consumed 157 international units or less vitamin D per day. The researchers found similar results for both boys and girls.

"These are adolescents who should have optimal pulmonary function," Dr Burns stated . "If they're already showing lower pulmonary function associated with lower vitamin D intake at this age, it may have long-term effects on their health."

"Vitamin D is promoted in terms of bone growth, but we also need to think in terms of vitamin D's other effects on the body," Dr. Burns adde d. "It may be that we should be promoting dietary vitamin D intake at recommended levels to ensure optimal lung function as well as to form and maintain healthy bones ."

"We don't know by which mechanism vitamin D affects pulmonary function--it's an area that needs to be explored," she noted.