PURPOSE: An antimutagenic agent, containing a vitamin B complex selected from thiamine pyrophosphate, folic acid and nicotinic acid as an active constituent, and capable of preventing mutagenicity caused by reaction of vitamin C with table luxuries or copper ions.
CONSTITUTION: An antimutagenic agent containing a vitamin B complex selected from thiamine pyrophosphate (hereinafter abbreviated to TPP), folic acid and nicotinic acid as an active constituent. TPP which is a diphosphoric acid ester of thiamine (vitamin B 1 ) and essential to the oxidative decarbonation and decomposition reaction of α-keto acids and folic acid, etc. are found to be capable of preventing the mutagenicity caused by vitamin C and usable as an antimutagenic agent. Thus, mutagenicity increased by reaction of coffee, black tea, tobacco, etc. with the vitamin C can be suppressed by mixing the above-mentioned vitamin B complex with the vitamin C.