Genetic polymorphisms of xenobiotic enzymes affect human vitamin C excretion.
This study describes the effect of gene polymorphisms on the metabolism of vitamin C. An oral loading of 1 mmol ascorbic acid (176 mg) or dehydroascorbic (174 mg) was given to 17 healthy females volunteers who had consumed a low vitamin C diet (vitamin C < 5 mg/day) for 3 days before loading. The urinary total vitamin C was determined. The urinary excretion of vitamin C (VC) was compared between ascorbic acid (AsA) and dehydroascorbic acid (DAsA), and the 24 hour total VC excretion was same. However gene polymorphisms of glutathione S-transferases P1 (GSTP1) showed the effect on that excretion. GSTP1 is one of xenobiotic enzymes in VC metabolism. The VC excretions in 24 hour after VC loading were greater (P < .01) in AA homozygotes of GSTP1 (46.7 +/- 18.1 mg) than GA heterozygotes (28.2 +/- 14.0 mg). On the single oral administration, the type of polymorphisms of GSTP1 has stronger effect on VC metabolism than the form of VC, DAsA and AsA. This study showed that determination of nutrient requirement needs to be considered with personal genotype.
Higasa
Shizu
S
High Technology Center, Kagawa Nutrition University, Japan.
Tsujimura
Masaru
M
Hiraoka
Mami
M
Nakayama
Kazuhiro
K
Yanagisawa
Yoshiko
Y
Iwamoto
Sadahiko
S
Kagawa
Yasuo
Y
D001205:Ascorbic Acid / Q000493:pharmacokinetics*; D003683:Dehydroascorbic Acid / Q000493:pharmacokinetics; D005260:Female; D051549:Glutathione S-Transferase pi / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D014815:Vitamins / Q000493:pharmacokinetics*; D055815:Young Adult
D014815:Vitamins; D051549:Glutathione S-Transferase pi; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid