Biological significance

Vitamin C is purely the L-enantiomer of ascorbate; the opposite D-enantiomer has no physiological significance. Both forms are mirror images of the same molecular structure. When L-ascorbate, which is a strong reducing agent, carries out its reducing function, it is converted to its oxidized form, L-dehydroascorbate.[6] L-dehydroascorbate can then be reduced back to the active L-ascorbate form in the body by enzymes and glutathione.[8]

L-ascorbate is a weak sugar acid structurally related to glucose which naturally occurs either attached to a hydrogen ion, forming ascorbic acid, or to a metal ion, forming a mineral ascorbate.