Vitamin K2 (VK2) is an essential co-factor for bone metabolism. There is still very little data regarding possible VK2 relation to periodontitis. This study aimed to investigate any potential link between VK2 serum level and the severity of periodontitis in comparison to a control group of healthy individuals. The trial was performed on 100 patients among whom 50 were diagnosed with periodontitis. The patients underwent full clinical periodontal and radiological examination. The VK2 serum level was assessed using the ELISA kit (Gla-type osteocalcin EIA Kit, Takara, Kusatsu). Patients with periodontitis had mean serum levels of VK2 significantly lower (0.27 ± 0.06 nmol/L; p < 0.001) than the control group (0.43 ± 0.09 nmol/L; p < 0.001) regardless of the patient's age or sex. The VK2 serum level decreased with the severity of periodontitis with the lowest level in stage IV of the disease (0.19 ± 0.01 nmol/L; p < 0.001). Also, a significant drop was noticed between the grades of periodontitis. Individuals with localized forms of the disease had significantly lower VK2 levels (0.26 ± 0.006 nmol/L; p < 0.001) in comparison to subjects with generalized periodontitis (0.30 ± 0.01 nmol/L; p < 0.001). The VK2 serum levels were also associated with most of the clinical parameters such as bleeding on probing (-0.805, 95% CI: -0.894 to -0.654, p < 0.001), attachment loss (-0.752, 95% CI: -0.862 to -0.574, p < 0.001), and bone loss (-0.656, 95% CI: -0.801 to -0.439, p < 0.001). In the present study, the VK2 serum level was correlated to periodontitis, and its severity, complexity, extension, and grade. The range of VK2 was decreasing together with the worsening of all clinical parameters of periodontitis.
Keywords: periodontitis; vitamin K2; vitamin K2 serum level.