OBJECTIVE This study was conducted to explore the relationship between 1,25-dihydroxy vitamin D (1,25(OH)2D) and Vitamin-D binding protein (DBP) in patients with periodontitis and healthy controls. METHODS Seventy-five periodontitis cases were recruited from the dental OPD of Dow University of Health Sciences, Karachi. Diagnostic criteria of periodontitis were followed according to the probe pocket depth and clinical attachment loss. Seventy-five periodontal healthy controls were selected from the faculty and students of same university. Serum levels of 1,25(OH)2D and DBP were determined by ELISA. RESULTS Significantly low levels of 1,25(OH)2D and high levels of serum DBP were observed in periodontitis patients compared to healthy controls (p<0.05), with levels of DBP increasing significantly with the severity of periodontitis (p=0.005). Concentrations of DBP correlated positively with 1,25(OH)2D, especially in cases with periodontitis (r =0.780; p<0.001). CONCLUSIONS Within the limits of the study, we conclude that low 1,25(OH)2D levels and high DBP levels are associated with periodontitis.