The Role of Serum Vitamin D Levels and Vitamin D Receptor (VDR) Gene Variants on Dental Caries

Background/Objectives: Vitamin D helps the mineralization of bone, teeth, and other calcified tissues by regulating calcium–phosphate metabolism. The nuclear activation of the vitamin D receptor (VDR) gene is essential for the effectiveness of vitamin D. The main objective of this study is to determine the role of vitamin D levels and VDR gene variants in dental caries. Methods: This study included 128 3–6-year-old children who were divided into 64 caries-free and 64 carious children. Blood samples were taken, and serum 25-hydroxyvitamin D levels were measured. Intraoral examinations were performed to record dmft index values. Genetic testing was performed on 26 children to examine VDR gene variations. Relevant gene regions were amplified using PCR and sequenced via Sanger sequencing in a total of 13 caries-free and 13 carious children. Stats analyses included chi-square/trend tests to compare count data; Student’s T/Mann–Whitney U tests for two-group normally/non-normally distributed data; and the Kruskal–Wallis test for 3+ groups with non-normal data. Results: The results showed that vitamin D levels were relatively low in the caries group, but no statistically significant relationship was found between vitamin D levels and caries. No mutations were detected in the VDR gene in either group, and there was no significant difference observed in terms of the number of ApaI, TaqI, and FokI polymorphisms. Based on these findings, the use of prophylactic vitamin D supplements to prevent caries formation or development cannot be recommended. Conclusions: This study provides important insights into the relationship between vitamin D and dental caries and can contribute to the development of effective preventive strategies for oral and dental health.