L-Ascorbic acid interrupts the chain reaction in the lipid peroxidation process
by giving an electron. It does this by blocking ‘‘free radicals’’ before
they reach the cellular membrane. AA functions as an antioxidant
by removing singlet oxygen, eliminating peroxy radicals formed
during lipid peroxidation and reducing a-tocopherol radicals to
a-tocopherol. Humans, and a few other mammals, do not have
the enzyme that converts glucose to vitamin C. In addition, GSH
can be converted to isoform in the presence of AA