Vitamin C pathway

The term **"Vitamin C pathway"** does not refer to a single molecular target such as a receptor, enzyme, transporter, or gene product. Instead, it encompasses all biochemical processes involved in the absorption, transport, cellular uptake, utilization (as an antioxidant and enzymatic cofactor), recycling/regeneration of reduced ascorbate from oxidized forms (dehydroascorbate), and eventual degradation/excretion of vitamin C. In humans and other primates who cannot synthesize vitamin C endogenously due to loss of L-gulonolactone oxidase activity[2], this network includes: • **Transporters:** Sodium-dependent vitamin C transporters SVCT1/SLC23A1 (intestinal/renal) and SVCT2/SLC23A2 (tissue uptake); glucose transporters GLUT1/GLUT3/GLUT4 mediate dehydroascorbate uptake via facilitated diffusion[1][3]. • **Enzymes:** Multiple monooxygenases/dioxygenases requiring ascorbate as a reducing agent/cofactor—key examples include prolyl hydroxylase for collagen synthesis; dopamine β-monooxygenase for norepinephrine production; enzymes involved in carnitine biosynthesis; peptidylglycine α-amidating monooxygenase for peptide hormone maturation; tyrosine metabolism enzymes[7]. • **Antioxidant function:** Ascorbate donates electrons directly to neutralize reactive oxygen species/free radicals generated during normal metabolism or under stress conditions. It also regenerates other antioxidants such as vitamin E from their oxidized forms.[5] Because “Vitamin C pathway” refers collectively to these interconnected processes rather than any one discrete molecular entity that could be considered a drug target per se—and because it lacks specificity regarding which component(s) are meant—it should be flagged as incorrect when compiling structured data on therapeutic targets. In summary: The “Vitamin C pathway” describes an essential metabolic network rather than an individual therapeutic target. For structured information about druggable targets within this system—such as sodium-dependent vitamin C transporter 1 (SVCT1), sodium-dependent vitamin C transporter 2 (SVCT2), or specific dioxygenases—a more precise name should be used.[1][3][9]

Other names

ascorbate metabolismascorbic acid biosynthesis and recyclingvitamin C metabolic pathway

Not applicable for the pathway as a whole; vitamin C acts as an antioxidant and enzyme cofactor within this network[3][5]