The FFQ, BLOCKIDS (NutritionQuest, University of Berkeley, Berkeley, CA), is comprised of foods identified by NHANES III as important for this age and demographic group. Of relevance to this project, measurements include dietary intake of Vitamin D and calcium. The FFQ has been validated in African American children ages 8-10 years (Block 2000) for some macro and micronutrients (e.g. correlation for calcium = 0.64). Additional validation studies are planned as part of the BMDHC project.