Serum vitamin D concentration is inversely associated with matrix metalloproteinase-9 level in periodontal diseases

Background: The aim of this study was to investigate the potential association between vitamin D deficiency and matrix metalloproteinase-9 (MMP-9) levels in gingival crevicular fluid (GCF) across various periodontal health and disease statuses. Methods: A total of 200 volunteers were divided into two groups according to serum vitamin D concentration (25(OH)D < 10 ng/mL and 25(OH)D >= 10 ng/mL). Periodontal health status was determined based on a full-mouth periodontal examination and radiographic evaluation. Participants in both groups were categorized according to periodontal diagnoses, encompassing periodontal health, gingivitis, and periodontitis. Following sampling, the MMP-9 levels in GCF were determined by the enzyme-linked immunosorbent assay (ELISA) method. Results: The GCF MMP-9 levels were found to be higher in individuals with serum 25(OH)D < 10 ng/mL, in both the healthy and gingivitis and periodontitis groups, compared to those with 25(OH)D >= 10 ng/mL. Nevertheless, a statistically significant distinction was observed exclusively within the gingivitis and periodontitis groups. Correlation analysis and robust regression analyses provided additional evidence supporting the predictive role of periodontal disease status and vitamin D concentration in local MMP-9 levels. These associations remained significant after adjusting for age and sex in robust regression analysis (p = 0.002). Furthermore, the inclusion of periodontal clinical parameters in the regression analysis revealed notable associations of clinical attachment loss with local MMP-9 levels, along with periodontal disease status and serum vitamin D concentration (p < 0.001). Conclusion: The findings of our study suggest a potential mechanistic relationship between serum vitamin D levels and periodontitis.