Ethnic differences in food sources of vitamin D in adolescent American girls: the National Heart, Lung, and Blood Institute Growth and Health Study.

The National Heart, Lung, and Blood Institute Growth and Health Study was a 10-year longitudinal study of the development of obesity and cardiovascular disease risk factors (including dietary, psychosocial, environmental, and others) in 2379 African American and white girls who were 9 or 10 years old at study entry. Current studies have documented a high prevalence of vitamin D insufficiency among healthy children, adolescents, and young adults in the United States, especially among low-income, black, and Hispanic children (defined as serum 25-hydroxyvitamin D concentrations of <20 ng/mL). Although the main source of vitamin D is direct exposure of the skin to ultraviolet rays from sunlight, certain foods contribute vitamin D including fortified milk, meat, eggs, oils, and fortified cereals. Vulnerable subgroups that are especially at risk for inadequate intakes of vitamin D include teenage girls and women. Research providing the prevalent food sources of vitamin D, especially in the diets of both white and African American female adolescents is limited. The purpose of this study is to document food sources of vitamin D reported by this biracial young cohort and compare potential ethnic or other differences that could enhance tailored dietary interventions that are particularly relevant to this vulnerable population subgroup.