Scurvy, once common among sailors and soldiers without access to foods containing vitamin C, is characterized by the formation of liver spots on the skin, spongy gums, and bleeding from all mucous membranes.
Vitamin C is the most widely taken nutritional supplement (Diet Channel 2007).
Vitamin C is produced from glucose by two main routes.
The richest natural sources of vitamin C are fruits and vegetables; of the former, the camu camu fruit and the Kakadu plum contain the highest concentration of the vitamin.
Vitamin C is specifically the L-enantiomer of ascorbate; the D-enantiomer has no physiological significance.
The intricate coordination in biological systems can be seen in the role of vitamin C in synthesis of collagen in humans.
In 1934, Hoffmann–La Roche became the first pharmaceutical company to mass-produce synthetic vitamin C, under the brand name of Redoxon.
Biological tissues that accumulate over 100 times the blood-plasma level of vitamin C include the adrenal glands, pituitary, thymus, corpus luteum, and retina (Hediger 2002).
Recommendations for vitamin C intake have been set by various national and international agencies.
Most simians consume vitamin C in amounts 10 to 20 times higher than those recommended by governments for humans (Milton 1999).
The ascorbate ion represents what is called the pharmacophore of vitamin C; that is, the structural feature (or set of features) responsible for the molecule’s biological activity (Gund 1977).
Along with vitamins A and E, and a group of related compounds called coenzyme Q, vitamin C also acts as a general (i.e., non-enzyme-specific) antioxidant.
Both processes yield approximately 60 percent vitamin C from the glucose feed (Competition Commission 2001).
Many pro-vitamin C organizations promote usage levels well beyond the current Dietary Reference Intake.
Research is underway to create a strain of yeast that can synthesize vitamin C in a single fermentation step from galactose, a technology expected to reduce manufacturing costs considerably.
Vitamin C acts as an electron donor for three enzymes participating in the synthesis of collagen.
The following table shows the relative abundance of vitamin C in different raw plant sources.
Trauma and injury have also been demonstrated to use up large quantities of vitamin C in humans (Long, et al.
The daily requirement and nutritional value of vitamin C are matters of ongoing debate.
The biological halflife for vitamin C is fairly short (about 30 minutes in blood plasma), a fact that mainstream researchers have failed to take into account according to high-dose advocates (Sardi 2004).
Another cause of vitamin C loss from food is a process called leaching, during which the water-soluble vitamin dissolves into the cooking water.
Vitamin C (or ascorbic acid) is a water-soluble vitamin required for a number of metabolic processes in living organisms.