Study DesignDescriptive cross-sectional study.PurposeTo determine the prevalence of vitamin D deficiency in patients with degenerative diseases of the spine about to undergo spinal surgery and the relations between such deficiency and potential risk factors.Overview of LiteratureVitamin D has a major role in musculoskeletal system health maintenance. Recently, studies on degenerative diseases of the spine have shown a high prevalence of vitamin D deficiency in patients undergoing spine surgery.MethodsSerum levels of 25(OH)D were determined by an electrochemiluminescence detection assay. The other variables were determined through relevant questionnaires, and the data was analyzed through analysis of variance, t-test, chi-square and multivariate logistic regression analysis.ResultsA total of 110 patients were enrolled in the study. The mean serum level of 25(OH)D was 27.45±18.75 ng/mL, and 44.5% of patients showed vitamin D deficiency (25(OH)D<20 ng/mL), with an additional 17.3% of patients having a serum level of 25(OH)D that was insufficient (20≤25(OH)D<30 ng/mL). The prevalence of vitamin D deficiency was significantly higher in the younger age group compared to the older age group (p<0.001) and the ones without a history of taking vitamin D supplements (p=0.013). Compared to men, women showed significantly higher levels of vitamin D (p=0.029).ConclusionsA high prevalence of vitamin D deficiency is seen in patients with degenerative diseases of the spine. On the other hand, the conventional risk factors such as old age or female sex alone did not seem to be sufficient in determining the likelihood of deficiency. Thus, it is recommended that vitamin D deficiency prevention strategies comprise a broader spectrum of the population through which such degenerative diseases and their consequences may be prevented or delayed.