A unique function for ascorbate

Abstract

Vitamin C is a reducing substance, an electron donor. When vitamin C donates its two high-energy electrons to scavenge free radicals, much of the resulting dehydroascorbate is re-reduced to vitamin C and therefore used repeatedly. Conventional wisdom is correct in that only small amounts of vitamin C are necessary for this function because of its repeated use. The point missed is that the limiting part in nonenzymatic free radical scavenging is the rate at which extra high-energy electrons are provided through NAD H to re-reduce the vitamin C and other free radical scavengers. When ill, free radicals are formed at a rate faster than the high-energy electrons are made available. Doses of vitamin C as large as 1–10 g per 24 h do only limited good. However, when ascorbate is used in massive amounts, such as 30–200+ per 24 h, these amounts directly provide the electrons necessary to quench the free radicals of almost any inflammation. Additionally, in high concentrations ascorbate reduces NAD(P) H and therefore can provide the high-energy electrons necessary to reduce the molecular oxygen used in the respiratory burst of phagocytes. In these functions, the ascorbate part is mostly wasted but the necessary high-energy electrons are provided in large amounts.