title: Relationships of nutrient intake and lifestyle-related factors to serum folate and plasma homocysteine concentrations in 30-69 year-old Japanese.
abstract: We studied non-hospitalized 30-69 y-old Japanese subjects to ascertain the influences of a 677C-T methylene-tetrahydrofolate reductase (MTHFR) genotype, nutritional intake and lifestyle-related factors on plasma homocysteine (Hcys) and serum folate concentrations. Hcys was higher and serum folate was lower in males than in females (p < .01). The Hcys concentration was higher in the VV group than in the AA and AV groups for both males and females. However, a relatively low serum folate concentration of 18 +/- 7 nmol/L was found in the entire male group as compared with 22 +/- 10 nmol/L in all females. In the female subjects, serum folate concentrations differed among MTHFR genotypes, being lowest in the VV group. In all male subjects, log folate intake per 1,000 kcal was a significant positive predictor of log serum folate concentration (p < 0.01), while in females the log vitamin C intake per standard body weight was a significant positive variable (p < 0.001) predicting the log serum folate concentration. Smokers had significantly lower serum folate concentrations, regardless of dietary folate intake. High folate and vitamin C consumptions, appears to be beneficial to normal and heterozygous MTHFR genotype subjects for maintaining serum folate concentrations. Even a 400 microg daily intake of folate might be less than what is needed, especially for homozygous MTHFR subjects and smokers, to maintain an adequate serum folate concentration.
authors.affiliation: Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan. maruyama@fc.jwu.ac.jp
authors.forename: Chizuko
authors.initials: C
authors.lastname: Maruyama
authors.forename: Risa
authors.initials: R
authors.lastname: Araki
authors.forename: Mayako
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Eriko
authors.initials: E
authors.lastname: Kuniyoshi
authors.forename: Akiko
authors.initials: A
authors.lastname: Iwasawa
authors.forename: Taro
authors.initials: T
authors.lastname: Maruyama
authors.forename: Satomi
authors.initials: S
authors.lastname: Nakano
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Motohashi
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Shingo
authors.initials: S
authors.lastname: Kyotani
authors.forename: Motoo
authors.initials: M
authors.lastname: Tsushima
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D001205:Ascorbic Acid / Q000008:administration & dosage; D004032:Diet; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood*; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007564:Japan; D008019:Life Style; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena; D011110:Polymorphism, Genetic; D012727:Sex Characteristics; D012907:Smoking / Q000097:blood; D014803:Vitamin B Complex / Q000008:administration & dosage
chemical_list: D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D001205:Ascorbic Acid