title: Low plasma vitamin B-12 is associated with a lower pregnancy-associated rise in plasma free choline in Canadian pregnant women and lower postnatal growth rates in their male infants.
abstract: BACKGROUND
  Choline needs are increased in pregnancy. Choline can be used as a source of methyl for homocysteine remethylation to methionine, but choline synthesis requires methyls from methionine. Vitamin B-12 deficiency increases choline use for homocysteine methylation.
  
  
  OBJECTIVE
  We investigated whether poor vitamin B-12 status occurs and contributes to low plasma choline and altered biomarkers of choline synthesis in pregnant women. With the use of a post hoc analysis, we addressed the association of maternal plasma vitamin B-12 status with postnatal growth rates in term infants.
  
  
  METHODS
  Blood was analyzed for a prospective study of 264 and 220 pregnant women at 16 and 36 wk of gestation, respectively, and 88 nonpregnant women as a reference.
  
  
  RESULTS
  The proportion of women with a plasma total vitamin B-12 concentration <148 pmol/L (deficient) or 148-220 pmol/L (marginal) increased with pregnancy and pregnancy duration, which affected 3% and 9% of nonpregnant women, 10% and 21% of women at 16 wk of gestation, and 23% and 35% of women at 36 wk of gestation, respectively. Plasma free choline, betaine, and dimethylglycine were lower in women at 36 wk of gestation with a deficient or marginal compared with sufficient plasma total vitamin B-12 concentration (>220 pmol/L). Plasma total vitamin B-12 was positively associated with the increase in plasma free choline from midgestation to late gestation (P < 0.001). The postnatal growth rate to 9 mo was lower in infant boys of women classified as total vitamin B-12 deficient compared with sufficient.
  
  
  CONCLUSIONS
  This study shows that maternal vitamin B-12 status is related to choline status in late gestation in a folate-replete population and may be a determinant of infant growth even in the absence of undernutrition.
authors.affiliation: Nutrition and Metabolism Research Program, Child and Family Research Institute, Department of Paediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Brian Tf
authors.initials: BT
authors.lastname: Wu
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Innis
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Mulder
authors.forename: Roger A
authors.initials: RA
authors.lastname: Dyer
authors.forename: D Janette
authors.initials: DJ
authors.lastname: King
mesh_terms: D000328:Adult; D001622:Betaine / Q000097:blood; D001955:British Columbia; D002657:Child Development / Q000187:drug effects*; D002794:Choline / Q000097:blood*; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000097:blood; D006801:Humans; D007223:Infant; D008297:Male; D008715:Methionine / Q000378:metabolism; D008875:Middle Aged; D011247:Pregnancy / Q000097:blood*; D011446:Prospective Studies; D012521:Sarcosine / Q000031:analogs & derivatives / Q000097:blood; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood*; D055815:Young Adult
chemical_list: D001622:Betaine; C025138:dimethylglycine; D005492:Folic Acid; D008715:Methionine; D002794:Choline; D014805:Vitamin B 12; D012521:Sarcosine