title: Vitamin B-6 Status in Unsupplemented Pregnant Women Is Associated Positively with Serum Docosahexaenoic Acid and Inversely with the n-6-to-n-3 Fatty Acid Ratio.
abstract: Vitamin B-6-deficient diets decrease plasma docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) concentrations in healthy adults. These fatty acids (FAs) are important for fetal neurodevelopment, but the relation between vitamin B-6 status and circulating polyunsaturated FAs (PUFAs) during pregnancy is unknown.
  
  
  
  We sought to assess the relation between plasma pyridoxal 5' phosphate (PLP; the active form of vitamin B-6) and serum DHA, EPA, AA, linoleic acid, eicosadienoic, and α-linolenic acid concentrations during pregnancy.
  
  
  
  A prospective cohort study in 186 healthy pregnant Brazilian women (aged 20-40 y) who were not using supplements was conducted in Rio de Janeiro, Brazil. Participants were enrolled in the first trimester of pregnancy (5-13 gestational weeks) and were followed up twice between 20-26 and 30-36 wk of gestation. Longitudinal linear mixed-effects regression models were used to evaluate the associations between 1) first-trimester PLP and PUFA concentrations across pregnancy and 2) ΔPLP (i.e., difference between third- and first-trimester plasma PLP concentrations) and PUFA concentrations across pregnancy. Models were adjusted for gestational week, first-trimester body mass index, smoking habit, and dietary intakes of vitamin B-6, fish, total fat, and PUFAs.
  
  
  
  Plasma PLP concentrations (median, IQR) substantially declined during pregnancy from 35.8 nmol/L (28.6-44.3 nmol/L) in the first trimester to 21.0 nmol/L (15.8-26.3 nmol/L) in the second trimester, and 16.8 nmol/L (12.9-20.3 nmol/L) in the third trimester (both P < 0.0001). Changes in plasma PLP concentrations across trimesters were positively associated with serum DHA concentrations (β = 0.252, P = 0.012) and inversely associated with serum n-6-to-n-3 (ω-6-to-ω-3) FA ratio (β = -0.010; P = 0.015), after adjustments for confounders.
  
  
  
  Maternal vitamin B-6 status during pregnancy was positively associated with the circulating concentration of DHA and inversely associated with n-6:n-3 FAs in Brazilian women who were not taking vitamin supplements. Further study is required to determine the impact of poor vitamin B-6 status on fetal neurodevelopment.
authors.affiliation: Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Mujica-Coopman
authors.affiliation: Nutrition Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|Emília de Jesus Ferreiro Nutrition School, Fluminense Federal University, Rio de Janeiro, Brazil.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Franco-Sena
authors.affiliation: Nutrition Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Dayana R
authors.initials: DR
authors.lastname: Farias
authors.affiliation: Nutrition Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|Faculty of Nutrition, Federal University of Pelotas, Rio Grande do Sul, Brazil; and.
authors.forename: Juliana S
authors.initials: JS
authors.lastname: Vaz
authors.affiliation: USDA, Western Human Nutrition Research Center, University of California at Davis, Davis, CA.
authors.forename: Alex
authors.initials: A
authors.lastname: Brito
authors.affiliation: Nutrition Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Kac
authors.affiliation: Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada; yvonne.lamers@ubc.ca.
authors.forename: Yvonne
authors.identifier: 0000-0001-7878-0164
authors.initials: Y
authors.lastname: Lamers
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004281:Docosahexaenoic Acids / Q000097:blood*; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D043371:Fatty Acids, Omega-6 / Q000097:blood*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D025101:Vitamin B 6 / Q000097:blood*; D055815:Young Adult
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D004281:Docosahexaenoic Acids; D025101:Vitamin B 6
keywords: DHA; EPA; PUFA; docosahexaenoic acid; eicosapentaenoic acid; n–3 fatty acids; polyunsaturated fatty acid; pregnancy; pyridoxal 5′-phosphate; vitamin B-6