In the United States, there are significant racial disparities in the incidence and prevalence of end-stage renal disease. The disparities are greatest for the Blacks and the magnitude of disparity is significantly greater than is evident from the incidence and prevalence data of end-stage renal disease - early stage chronic kidney disease is less common in Blacks and during that stage, mortality rate is significantly higher for that racial group. Recent studies have identified a genetic predisposition for non-diabetic renal disease among Blacks. However, genetic factors explain only part of the higher risk and the racial disparities are a result of a complex interplay of biology and sociology. Herein we focus on two factors and their role in explaining the higher risk for progression of chronic kidney disease among Blacks - one biologic (vitamin D deficiency) and one sociologic (neighborhood poverty). A greater Understanding of these factors is important in order to reduce the racial disparities in the United States.