Vitamin C and cancer revisited - 0 views
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It is well known that vitamin C, or ascorbic acid, is an effective biologic antioxidant and does not act as a pro-oxidant under normal conditions (5) because it does not readily autoxidize, i.e., react with oxygen (O2) to produce reactive oxygen species, such as superoxide radicals (O2•−) or H2O2
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However, ascorbate readily donates an electron to redox-active transition metal ions, such as cupric (Cu2+) or ferric (Fe3+) ions, reducing them to cuprous (Cu+) and ferrous (Fe2+) ions, respectively
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Reduced transition metal ions, in contrast to ascorbic acid, readily react with O2, reducing it to superoxide radicals (Reaction 2), which in turn dismutate to form H2O2 and O2
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