title: Relationship between dietary folate intakes, maternal plasma total homocysteine and B-vitamins during pregnancy and fetal growth in Japan.
abstract: BACKGROUND
  Adequate folate status in pregnancy is important for satisfactory pregnancy outcome.
  
  
  OBJECTIVE
  The objective of the present study was to evaluate folate status in healthy pregnant women by assessing dietary folate intakes and measuring changes in folate-related biomarkers including plasma tHcy, serum vitamin B(12) (B(12)), and serum and RBC folate concentrations in each trimester and to examine their relation to fetal growth.
  
  
  METHODS
  From 94 pregnant women, 3-day-dietary records were obtained and blood was collected for plasma total homocysteine (tHcy), serum B(12), and serum and red-blood cell (RBC) folate measurements. Infant anthropometric measurements were made immediately after birth.
  
  
  RESULTS
  Average folate intake was less than 300 microg/day with a mean energy intake of about 1800 kcal. Mean serum and RBC folate concentrations declined significantly during gestation (p < 0.05). Mean serum B(12) also significantly decreased (p < 0.01), whereas plasma tHcy increased from 5.1 in the first trimester to 5.9 micromol/l in the third trimester (p < 0.01). Multiple regression analyses, after controlling for maternal age, parity and pre-pregnancy body-mass index indicated that a 1.0 micromol/l increase in plasma tHcy in the third trimester corresponded to a 151 g decrease in birth weight (p < 0.01). Neither B(12) nor folate concentrations in all three trimesters showed any significant associations with birthweight. Plasma pyridoxal-5'-phosphate concentrations were markedly low, and were consistent with low intake of vitamin B(6) in our population.
  
  
  CONCLUSIONS
  Our data suggest that higher plasma tHcy in the third trimester is a predictor of lower birth weight. In general, the dietary intake of B-vitamins and energy may be inadequate in our population, suggesting intervention is necessary.
authors.affiliation: Dept. of Health Promotion and Research, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama, 351-0197, Japan. thidemi@niph.go.jp
authors.forename: Hidemi
authors.initials: H
authors.lastname: Takimoto
authors.forename: Natsuko
authors.initials: N
authors.lastname: Mito
authors.forename: Keizo
authors.initials: K
authors.lastname: Umegaki
authors.forename: Asako
authors.initials: A
authors.lastname: Ishiwaki
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kusama
authors.forename: Shiro
authors.initials: S
authors.lastname: Abe
authors.forename: Machi
authors.initials: M
authors.lastname: Yamawaki
authors.forename: Hideoki
authors.initials: H
authors.lastname: Fukuoka
authors.forename: Chitaru
authors.initials: C
authors.lastname: Ohta
authors.forename: Nobuo
authors.initials: N
authors.lastname: Yoshiike
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001724:Birth Weight; D015992:Body Mass Index; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D047109:Fetal Development / Q000187:drug effects / Q000502:physiology*; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D009752:Nutritional Status; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D014805:Vitamin B 12 / Q000097:blood; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000097:blood
chemical_list: D015415:Biomarkers; D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid; D014805:Vitamin B 12