title: Vitamin C: the nontoxic, nonrate-limited, antioxidant free radical scavenger.
abstract: The amount of oral ascorbic acid that a patient can tolerate without diarrhea, increases somewhat proportionately to the "toxicity" of his disease. Clinically, in a disease ameliorated by ascorbate, there is a suppression of symptoms only with very high doses and approximately to that extent which a nonrate-limited, antioxidant free radical scavenger, might be expected to affect that disease process if all harmful free radicals and highly reactive oxidizing substances were quenched. In most pathologic processes, the rate at which free radicals and highly reactive oxidants are produced, exceeds the rate at which the ordinary rate-limited antioxidant free radical scavenging mechanisms can quench those free radicals and oxidants. When ascorbate acts as a scavenger, dehydroascorbate is formed; but if the ascorbate/dehydroascorbate (AA/DHA) ratio is kept high (the redox potential kept reducing) until the unstable dehydroascorbate undergoes hydrolysis or can be reduced back to ascorbate, the dehydroascorbate will do no harm. Since even at very high doses, ascorbate is virtually nontoxic, it may be given in the enormous doses necessary to quench almost all unwanted free radicals and oxidants. The wide spectrum of infectious diseases ameliorated by massive doses of ascorbate indicates some common pathologic processes in these diseases.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000628:therapy; D000975:Antioxidants; D001205:Ascorbic Acid / Q000627:therapeutic use* / Q000633:toxicity; D001206:Ascorbic Acid Deficiency / Q000378:metabolism; D003967:Diarrhea / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D005609:Free Radicals; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000188:drug therapy; D006801:Humans; D007223:Infant; D007669:Kidney Calculi / Q000188:drug therapy; D007700:Kinetics; D010084:Oxidation-Reduction; D012614:Scurvy / Q000209:etiology; D013398:Sudden Infant Death
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D001205:Ascorbic Acid