Identification of variants within genes SLC23A1 and SLC23A2 coding for vitamin C transporter proteins associated with aggressive (AgP) and chronic periodontitis (CP).Employment of three independent case-control samples of AgP (I. 283 cases, 979 controls; II. 417 cases, 1,912 controls; III. 164 cases, 357 controls) and one sample of CP (1,359 cases, 1,296 controls).Stage 1: Among the tested SNPs, the rare allele (RA) of rs6596473 in SLC23A1 showed nominal significant association with AgP (p = 0.026, odds ratio [OR] 1.26, and a highly similar minor allele frequency between different control panels. Stage 2: rs6596473 showed no significant association with AgP in the replication with the German and Dutch case-control samples. After pooling the German AgP populations (674 cases, 2,891 controls) to significantly increase the statistical power (SP = 0.81), rs6596473 RA showed significant association with AgP prior to and upon adjustment with the covariates smoking and gender with padj = 0.005, OR = 1.35. Stage 3: RA of rs6596473 showed no significant association with severe CP.SNP rs6596473 of SLC23A1 is suggested to be associated with AgP. These results add to previous reports that vitamin C plays a role in the pathogenesis of periodontitis. This article is protected by copyright. All rights reserved.