Vitamin C Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin C, including details on benefits, dosage, supplements, information.

Polymorphism of glutathione S-transferase P1 gene affects human vitamin C metabolism.

Higasa S, Tsujimura M, Hiraoka M, Nakayama K, Yanagisawa Y, Iwamoto S, Kagawa Y

High Technology Center, Kagawa Nutrition University, 3-9-21 Chiyoda, Sakado-city, Saitama-ken 350-0288, Japan.

There are large inter-individual differences in the metabolism of vitamin C (VC), which is composed of both ascorbic acid (AsA) and dehydroascorbic acid (DAsA). AsA is oxidized to DAsA in a series of xenobiotic reactions. Thus, the effects of polymorphism A313G (Ile105Val) in the gene for glutathione S-transferases P1 (GSTP1), one of the most active xenobiotic enzymes, on human VC metabolism were studied. The variant frequency of GSTP1 among the present subjects (n=210) was AA 71.0%; GA 27.0% and GG 1.9%. At 24 h after administration of 1 mmol of VC to young women (n=17; age, 21.0+/-1.1 y), total VC excretion (46.7+/-18.1mg) by AA homozygotes of GSTP1 was greater (p<0.0069) than that (28.2+/-14.0 mg) by GA heterozygotes. One hour after administration of VC, blood total VC levels were also significantly different (p<0.0036) between the homozygotes and heterozygotes. The effects of other polymorphisms in xenobiotic enzymes on VC metabolism were small.

Published 7 November 2007 in Biochem Biophys Res Commun, 364(3): 708-13.
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