Sodium-dependent vitamin C transporter (SVCT)

Vitamin C transporters are specialized membrane proteins that mediate the cellular uptake of vitamin C, an essential micronutrient for humans (Bürzle et al., 2013, PMID: 23603813). The primary transporters are the sodium-dependent vitamin C transporters, SVCT1 (SLC23A1) and SVCT2 (SLC23A2), which transport the reduced form, L-ascorbic acid, against a concentration gradient using the sodium electrochemical potential (Savini et al., 2008, PMID: 18353311). SVCT1 is predominantly expressed in epithelial tissues like the small intestine and proximal renal tubules, where it regulates systemic vitamin C levels through absorption and reabsorption. In contrast, SVCT2 is ubiquitously expressed, particularly in the brain, eye, and neuroendocrine tissues, ensuring high intracellular concentrations required for its role as a cofactor for enzymes involved in collagen synthesis and neurotransmitter metabolism (May, 2011, PMID: 21382153). Additionally, certain glucose transporters (GLUT1, GLUT3, and GLUT4) can transport the oxidized form, dehydroascorbic acid, which is subsequently reduced to ascorbic acid within the cell (Nualart et al., 2014, PMID: 24801992). These transporters are critical for maintaining redox balance and protecting cells from oxidative damage. Genetic polymorphisms in SVCTs have been associated with increased risks of chronic diseases, and their role in cancer therapy is a subject of intense research, as high-dose vitamin C may selectively target cancer cells through transporter-mediated uptake.

Other names

SLC23 familySolute carrier family 23Sodium/ascorbate cotransporterAscorbic acid transporterSVCT1SVCT2

Facilitation of cellular uptake of L-ascorbic acid via sodium-dependent active transport (SVCTs) or dehydroascorbic acid via facilitated diffusion (GLUTs).