ABSTRACT
I. INTRODUCTION A. Vitamin C Is a Potent Water-Soluble Antioxidant Vitamin C (ascorbate) is an essential micronutrient required for normal metabolic functioning of the body (1). Humans, and other primates, have lost the ability to synthesize vitamin C owing to a mutation in the gene coding for l-gulono-γ -lactone oxidase, an enzyme required for the biosynthesis of vitamin C via the glucuronic acid pathway (2). As a result, humans have to obtain vitamin C through the diet; the vitamin is especially plentiful in fresh fruit and vegetables (3). A lack of vitamin C in the diet causes the deficiency disease scurvy (4). Vitamin C is a cosubstrate for various biosynthetic enzymes, including the hydroxylases and oxygenases involved in the synthesis of collagen, carnitine, and catecholamines (5,6). The role of vitamin C is to reduce the active center metal ion of these enzymes (5,6), and the ability to maintain metal ions in the reduced state is related to the redox potential of vitamin C (7).
