Serum 25-hydroxyvitamin D Levels in Patients with Pterygium: A Systematic Review and Meta-Analysis

Abstract

Purpose: To compare serum vitamin D levels between pterygium (PTG) patients and healthy controls, given vitamin D’s immunomodulatory properties and the ultraviolet-mediated pathogenesis of PTG through a systematic review and meta-analysis. Methods: A systematic search was conducted in PubMed, Web of Science, and Scopus up to July 25, 2025. All observational studies measuring vitamin D levels in patients with PTG were included. The mean difference (MD) analysis was calculated using a random-effects model to assess the differences in vitamin D levels between patients with PTG and healthy controls. Results: Eight relevant studies with 2814 patients were included in this meta-analysis. The findings were inconsistent, with three studies reporting significantly higher vitamin D levels in PTG patients compared to healthy controls, three studies finding no association, and two studies indicating a significant deficiency in PTG patients. The results of the meta-analysis revealed no statistically significant differences in mean serum vitamin D levels between PTG patients and healthy controls (MD = − 0.81, 95 CI − 3.48 to 1.85, p = 0.55). The meta-regression analysis revealed significant associations between vitamin D levels and age in patients with PTG. Conclusion: Current evidence does not support a statistically significant difference in serum vitamin D levels between patients with PTG and healthy controls. However, the analysis was limited by substantial heterogeneity. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.