Vitamin D deficiency as a risk factor for idiopathic carpal tunnel syndrome: A case-control study

Abstract Background Vitamin D (VD) plays essential roles in neurological health and may influence nerve function through both neuroprotective mechanisms and anti-inflammatory. Objective To investigate the association between VD deficiency and idiopathic CTS, evaluate the independent relationship of low serum levels of VD with CTS risk and symptom severity. Methods A case-control investigation was taken place with 80 participants, comprising 40 clinically suspected CTS patients with normal electrodiagnostic findings and 40 healthy controls, recruited from Al Zahraa University Hospital between November 2023 and July 2024. The levels of serum 25-hydroxyvitamin D were compared between groups. Correlations were assessed using Pearson's correlation coefficient for VD levels relative to clinical parameters, including disease duration and median nerve cross-sectional area (CSA). Results Patients with CTS had significantly reduced serum 25-hydroxyvitamin D levels (12.57 ± 3.21 ng/mL) compared to controls (24.02 ± 3.07 ng/mL), (p< 0.001), indicating a high prevalence of deficiency among CTS patients. Disease duration was inversely correlated with serum 25-hydroxyvitamin D levels (r = -0.512, p < 0.001), suggesting that lower VD levels corresponded with longer symptom duration. No significant relationships were detected between VD levels and wrist median nerve CSA (r = -0.030, p = 0.855) or in the forearm (r = 0.118, p = 0.470), indicating that VD deficiency may not be directly related to structural nerve changes in CTS patients. Conclusion VD deficiency is significantly correlated with idiopathic CTS, particularly with disease duration. These data suggest the role of VD as a modifiable risk factor, suggesting the need for further research into VD supplementation as a therapeutic intervention for CTS management. Keywords Carpal tunnel syndrome, vitamin D deficiency, 25-hydroxyvitamin D, neuropathy, neuroprotective properties.