The reduced form of vitamin C is transported into cells via sodium-dependent vitamin C transporters (SVCT1 and SVCT2) (Figure 3). SVCT1 (the product of the SLC23A1 gene in humans) is mainly expressed in intestinal and renal epithelial cells, where it helps to mediate absorption and re-absorption of the vitamin, respectively. SVCT2 (the product of the SLC23A2 gene in humans) is found in cells of most other tissues, including the brain. Both SVCT1 and SVCT2 mediate high affinity, sodium- and energy-dependent transport of vitamin C into cells and are essential to establish steep concentration gradients of vitamin C across the plasma membrane [5]. SVCTs, particularly SVCT2, may also transport vitamin C from the cytosol into the mitochondrial matrix