The Influence of Vitamin D Levels on Dental Caries: A Retrospective Study of the United States Population.

(1) Background: This study examines vitamin D's impact on dental caries to inform prevention strategies, given its critical role in bone and calcium regulation, vital for dental health. (2) Methods: Data from 18,683 participants of the National Health and Nutrition Examination Survey (NHANES) 2011-2016 were analyzed. NHANES collects U.S. population data through interviews, physical exams, and tests, including vitamin D levels and dental health assessed using both the decayed, missing, and filled teeth (DMFT) index and the presence of untreated dental caries. Vitamin D levels were measured according to serum 25(OH)D concentrations, and the analyses adjusted for confounders such as body mass index (BMI) and socioeconomic status (SES) using Chi-square, Mann-Whitney U, Kruskal-Wallis tests, as well as logistic and Poisson regression. (3) Results: This study found a mean DMFT score of 7.36 and a 33.2% prevalence of untreated dental caries. A higher caries prevalence was correlated with a lower SES ( p < 0.001), the male gender ( p < 0.001), and a higher BMI ( p < 0.001). Severe vitamin D deficiency (<25 nmol/L) doubled the risk of dental caries, with odds ratios of 2.261 and 1.953 after adjusting for demographic factors and BMI. (4) Conclusions: Our study confirms a significant relationship between low vitamin D levels and an increased risk of dental caries nationwide, even after accounting for sociodemographic factors, emphasizing the importance of maintaining sufficient vitamin D levels for preventing caries.