This study explored the association between vitamin D insufficiency and frailty syndrome defined by the Fried Frailty Index (FFI) and the Edmonton Frail Scale (EFS) in a northern Taiwan community. Data of 215 subjects participating in an integrated interventional trial involving community-dwelling older adults with a high frailty risk were analyzed. Subjects were first screened by telephone interview and then evaluated at a local hospital with questionnaires, physical performance tests, and serum 25(OH)D measurements. Of the 215 participants, 31% had 25(OH)D insufficiency (< 20 ng/ml). Frail subjects based on the FFI were older, had lower Mini-Mental Status Exam (MMSE) scores, Barthel Index (BI) scores, and 25(OH)D levels. Using the EFS, frailer cases were more likely to be female, have less education, higher comorbid conditions, lower MMSE scores, lower Barthel Index scores, and lower 25(OH)D levels. The associations between insufficient 25(OH)D status and both frailty scales were significant. After adjustment of variables, the odds ratio of 25(OH)D insufficiency was 10.74 (95% CI 2.60-44.31) for frail versus robust individuals. The prevalence of vitamin D insufficiency was high in this population. There was a strong association between vitamin D insufficiency and the FFI. Vitamin D measurements and supplements are suggested for high-risk older people.