SLC23A1 encodes SVCT1 (sodium-dependent vitamin C transporter 1), a membrane transporter that specifically mediates cellular uptake of L-ascorbic acid (vitamin C) but not its efflux 1. The protein functions as a sodium-coupled transporter with high specificity for the reduced form of vitamin C, distinct from dehydroascorbic acid transporters in the GLUT family 2. SLC23A1 shows widespread tissue expression with particularly high levels in brain and kidney, where it localizes to the apical membrane of proximal tubular epithelial cells and is responsible for vitamin C reabsorption 13. Structural analysis reveals the protein exists primarily as a monomer with minor dimeric populations when purified from expression systems 4. Genetic variation in SLC23A1, particularly the rs33972313 polymorphism, significantly influences circulating L-ascorbic acid concentrations, with each minor allele associated with approximately 6 μmol/L reduction in vitamin C levels 56. Unlike SLC23A2, SLC23A1 tolerates non-synonymous variants, suggesting different evolutionary selective pressures 7. The transporter plays a crucial role in maintaining systemic vitamin C homeostasis, which is essential for antioxidant defense and various enzymatic functions 8.