Objective: The aim of this study was to investigate the association between single-nucleotide polymorphisms (SNPs) in vitamin D metabolic pathway genes, serum 25-hydroxyvitamin D [25(OH)D] concentrations, and leukocyte telomere length (LTL) in Brazilian adults. Methods: The study population comprised 461 participants (33 79 y of age; 51% women) from the Pr o-Sa ude Study, a cohort of civil servants at a university campus in Rio de Janeiro, Brazil. LTL, genotypes of vitamin Drelated SNPs (rs12785878, rs10741657, rs6013897, and rs2282679), and serum 25(OH)D concentrations were determined cross-sectionally. Differences in age- and sex-adjusted LTL means by categories of genotypes and 25 (OH)D serum concentrations were evaluated. LTL associations with genotypes and 25(OH)D were investigated using multiple linear regression models adjusted for sociodemographic characteristics and markers of health behavior. Results: Participants with CC genotype (rs2282679) had shorter age- and sex-adjusted mean LTL than those with AC and AA genotypes (mean § SE: 0.51 § 0.03, 0.58 § 0.01 and 0.5 § 0.01, respectively, P < 0.05). In adjusted analyses, the CC genotype (rs2282679) was inversely associated with LTL (b = 0.061; 95% confidence interval, 0.120 to 0.001). Other vitamin D-related SNPs and serum 25(OH)D concentrations were not associated with LTL. Conclusions: Genetic variations in the gene encoding vitamin D binding protein (GC - rs2282679) were associated with LTL, suggesting an influence of vitamin D status on telomere length that may start early in life.