Association Between Vitamin D Deficiency and Outcomes Following Spinal Fusion Surgery: A Systematic Review

Background Vitamin D deficiency is a relatively common occurrence in patients presenting for spinal surgery; however, whether this abnormality has any effect on spinal fusion outcomes remains unclear. We performed a systematic review of the available literature relevant to the association between vitamin D deficiency and spinal fusion outcomes. Methods We conducted a systematic and critical review of recent literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following databases were searched: MEDLINE/PubMed, Google Scholar, Cochrane, Web of Science, and Scopus. Key search terms were “vitamin D,” “spinal surgery outcomes,” “spinal fusion,” and “pseudarthrosis.” Papers included in the review were original research articles in peer-reviewed journals. The articles were thoroughly examined and compared on the basis of study design, outcomes, and results. Results A total of 5 studies were included in the qualitative analysis. In these studies, patients presenting with vitamin D deficiency achieved lower fusion rates and suffered higher rates of recurrent-persistent low back pain compared with patients with normal vitamin D levels. Studies examining the effect of postoperative vitamin D supplementation in deficient patients reported significant improvements in low back pain intensity, patient-reported outcomes scores, and fusion rates compared with baseline as well as with control groups. Conclusions The literature suggests that patients presenting for spinal fusion may benefit from correction of vitamin D deficiency to maximize the chance of a successful arthrodesis and to achieve optimal surgical outcomes. Future prospective studies are needed to determine whether routine preoperative treatment of this metabolic derangement is warranted.