Vitamin D levels in patients with periodontal disease and dark skin

Periodontal diseases are prevalent chronic inflammatory conditions. Vitamin D deficiency may influence immune and bone pathways relevant to periodontal pathology, and cutaneous synthesis can be reduced in individuals with darker skin phototypes. The present study investigated serum vitamin D levels in patients with the dark skin phototype diagnosed with periodontitis. The present cross‑sectional study included 79 adults. A survey was applied regarding sources of vitamin D intake and skin phototype according to the Fitzpatrick scale. Periodontal indicators were clinically assessed, and serum vitamin D levels were measured using ELISA. Statistical analyses included two‑sided Fisher's exact tests for categorical associations and one‑way ANOVA and Kruskal‑Wallis tests for vitamin D comparisons, with Tukey's HSD and Dunn‑Bonferroni post hoc tests, respectively (α=0.05). The results revealed that 89.9% of the patients did not report risk habits, such as smoking. As regards the oral diagnosis, 10.1% of the patients were healthy, 41.8% had gingivitis, 44.3% had stage I‑II periodontitis 3.8% had stage III‑IV periodontitis. The mean vitamin D level was 22.6±7.1 ng/ml; 83.5% of patients had insufficient vitamin D levels. The vitamin D levels differed across the diagnostic groups (P=0.005 and P=0.00051), with lower levels observed in patients with periodontitis and gingivitis. No significant associations were found between vitamin D sources and periodontal diagnosis (dairy borderline, P=0.054). Phototype distributions differed across the diagnostic categories; however, phototype was not associated with vitamin D categories. On the whole, insufficient vitamin D levels were common, and levels were lower in those with advanced‑stage periodontitis. These findings support considering the vitamin D status in periodontal care for patients with darker skin phototypes and motivate longitudinal, multivariable studies with validated dietary assessment to clarify causal pathways and test targeted interventions.