OBJECTIVES: To evaluate the current national trends in Vitamin D prescribing among the elderly seeking care in office-based physician provider settings. METHODS: Cross-sectional study was conducted using the National Ambulatory Medical Care Survey (NAMCS) data from 2000 to 2009.  All ambulatory office visits made by the elderly aged ≥65 years of age were included in the study. Bivariate associations between vitamin D and study variables such as patient demographics, region, physician’s specialty, insurance status, and osteoporosis diagnosis were evaluated using chi square tests.  Logistic regression analyses were conducted to determine the predictive factors associated with a vitamin D. All analyses were performed with SAS statistical software, version 9.1, at an alpha of 0.05.  RESULTS: Of the 279,819 office-based physician visits made by the NAMCS participants from 2000 through 2009, there were 74,904(26.7%) visits that met the inclusion criteria. This estimate represented 2.4 billion physician-office visits from the elderly in the United States during the 10-year period. Of the included visits, 1,112 (1.91%) were associated with a vitamin D. Race was a significant predictor in both the adjusted and unadjusted models. Visits from other races were two times more likely to include vitamin D when compared to white race (Adjusted OR = 1.54; 95% CI 1.17-2.03), while visits made by black patients were less likely to include vitamin D therapy (Adjusted OR = 0.43; 95% CI 0.38-0.50). The visits made by osteoporosis patients were five times more likely to be associated with vitamin D therapy than visits made by patients without the diagnosis  (Adjusted OR=5.23; 95% CI 4.04-6.77). CONCLUSIONS: This study indicated that very few patients were prescribed vitamin D. The overall prescribing patterns of vitamin D therapy, however, showed a steady and continuous increase during past decade in the United States.