Scurvy

Abstract: The recognition of vitamin C is associated with a history of an unrelenting search for the cause of the ancient haemorrhagic disease scurvy. Isolated in 1928, vitamin C is essential for the development and maintenance of connective tissues. It plays an important role in bone formation, wound healing and the maintenance of healthy gums. Vitamin C plays an important role in a number of metabolic functions including the activation of the B vitamin, folic acid, the conversion of cholesterol to bile acids and the conversion of the amino acid, tryptophan, to the neurotransmitter, serotonin. It is an antioxidant that protects body from free radical damage. It is used as therapeutic agent in many diseases and disorders. Vitamin C protects the immune system, reduces the severity of allergic reactions and helps to fight off infections. However the significance and beneficial effect of vitamin C in respect to human disease such as cancer, atherosclerosis, diabetes, neurodegenerative disease and metal toxicity however remains equivocal. Thus further continuous uninterrupted efforts may open new vistas to understand its significance in disease management.

Abstract: ▪ Abstract Vitamin C is an essential dietary nutrient required as a co-factor for many enzymes, and humans are among the few animals that lack the ability to synthesize the compound from glucose. The reduced form of the vitamin, ascorbic acid, is an especially effective antioxidant owing to its high electron-donating power and ready conversion back to the active reduced form. Concentrations of the vitamin in body tissues and fluids are regulated through interactions of intestinal absorption, cellular transport, and excretion. The amount of vitamin C needed to prevent scurvy is very small and easily obtained in nearly all Western diets. There is great interest in the clinical roles of vitamin C because of evidence that oxidative damage is a root cause of, or at least associated with, many diseases. Population studies show that individuals with high intakes of vitamin C have lower risk of a number of chronic diseases, including heart disease, cancer, eye diseases, and neurodegenerative conditions. However, these results may simply reflect a more healthful diet or lifestyle for individuals with a high vitamin C intake. At present, data from controlled clinical trials have not established that higher intakes of vitamin C alone will help prevent chronic degenerative diseases. However, the evidence that ascorbic acid acts as an important antioxidant in many body tissues is convincing. The new higher Recommended Dietary Allowance (RDA) for vitamin C of 75 mg for women and 90 mg for men is, for the first time, based on the vitamin's role as an antioxidant as well as protection from deficiency. In healthy people, amounts greater than the RDA do not appear to be helpful. Vitamin C nutriture may be more important for people with certain diseases or conditions. High intakes of the vitamin are generally well tolerated; a Tolerable Upper Level was recently set at 2 g based on gastrointestinal upset that sometimes accompanies excessive intakes.

Abstract: History of vitamin C: a history of scurvy and vitamin C. Chemistry and biochemistry: an overview of ascorbic acid chemistry and biochemistry antioxidant and prooxidant properties of vitamin C the vitamin C radical and its reactions vitamin C and redox cycling antioxidants regeneration of vitamin C protein glycation by the oxidation products of ascorbic acid ascorbate membrane transport properties. Physiology and biomedical aspects: vitamin C as an antiatherogen - mechanisms of action protection of human low-density lipoprotein from oxidative modification by vitamin C diet and oxidative damage to DNA - the importance of ascorbate as an antioxidant vitamin C, collagen biosynthesis and aging oxidative stress and ascorbate in relation to risk for cataract and age-related maculopathy antioxidant action of vitamin C in the lung vitamin C and asthma effect of vitamin C on leucocyte function and adhesion to endothelial cells. Nutrition and health: human metabolism and the requirement for vitamin C vitamin C safety in human vitamin C in prospective epidemiological studies nitrogen oxides are important contributors to cigarette smoke-induced ascorbate oxidation vitamin C and cigarette smoke exposure vitamin C, smoking, and alcohol consumption. (Part contents).

Abstract: Introduction History of Vitamin C and its Role in the Prevention and Cure of Scurvy Discovery and Structure of Vitamin C Synthesis, Manufacture and Further Chemistry of Vitamin C Biochemistry of Vitamin C Inorganic and Analytical Aspects of Vitamin C Chemistry Bibliography Index.