Objective: Benign paroxysmal positional vertigo (BPPV) is characterized by recurrent attacks of vertigo caused by head movements. It occurs as a result of otoconia falling into the semicircular canal. Calcium and 25 hydroxyvitamin D [25(OH)D] metabolism in the inner ear play an important role in otoconia formation and degeneration. Our aim in this study was to investigate the relationship between 25(OH)D levels and BPPV. Methods: This retrospective, case-controlled study included 52 patients with posterior canal BPPV and 52 controls aged 18 to 80 years. Age, sex, serum calcium, corrected calcium, and 25(OH)D levels of the BPPV and control group were compared. Results: Twenty-three of the patients were male (44.2%) and 29 were female (55.8%). The average age was 55.6 years. The 25(OH)D level was 15.3 ng/mL in the BPPV group and 20.2 ng/mL in controls. There was no significant difference in 25(OH)D and albumin-corrected calcium values (P = .394; P = .084, respectively). In 80.7% of the BPPV group and 61.5% of the controls, 25(OH)D levels were 20 ng/mL and below. 25 hydroxyvitamin D deficiency was found statistically significantly more frequently in patients with BPPV (P = .030). Conclusion: In our study, serum 25(OH)D levels were found to be lower in patients with BPPV, and the rate of vitamin D deficiency was higher in these patients. Based on these results, it is recommended to examine the 25(OH)D levels of patients with BPPV at the time of diagnosis.