Childhood fractures are common, result in substantial costs and morbidity and appear to be increasing in incidence. Recent studies suggest that elevated fracture risk in otherwise healthy children is a function of lower bone mineralization. Because the majority of bone mineralization occurs before adulthood, poor bone health in childhood also negatively impacts adult bone health and may increase the risk of adult fractures associated with osteoporosis. Early identification of children with poor bone health may allow early intervention with important long term benefits. African American children, in particular, may be at higher risk of poor bone health due to both environmental and genetic factors. The overall objective of this case-control study is therefore to compare bone health in urban African American children with and without traumatic fractures to evaluate the hypothesis that African American children with forearm fractures are more likely to have deficient bone health than fracture-free controls. Specific Aim 1: Determine the association between forearm fracture in African American children and environmental predictors of bone health. Hypothesis 1: Cases will have significantly higher body mass index, significantly lower dietary intake of calcium/vitamin D and significantly less sun exposure than controls. Specific Aim 2: Determine the prevalence of vitamin D deficiency and decreased bone density (BMD) among cases and controls. Hypothesis 2: Cases will have a significantly higher prevalence of vitamin D deficiency and a significantly lower BMD than controls. Specific Aim 3: Investigate the association between forearm fracture in African American children and the F allele vitamin D receptor gene polymorphism. Hypothesis 3: Cases will have significantly more prevalent F allele SNP than controls. This proposal is unique in its investigation of the relationship between bone health and childhood fractures through a systematic evaluation of bone health in a vulnerable population. Further elucidating the association between bone health deficits and fractures in at-risk children would enable targeted intervention, which may decrease fracture rates, both in later childhood and in adulthood. Furthermore, the results of this research could promote effective prevention through screening and the expansion of injury prevention strategies to recognize underlying medical conditions contributing to risk.