title: Determinants of cobalamin status in newborns.
abstract: OBJECTIVE
  Cobalamin deficiency accompanied by bone marrow dysfunction and impaired central nervous system development has been reported in infants who were born to mothers with low cobalamin intake. We investigated the relation between cobalamin status in newborns and in their healthy mothers who consumed an omnivorous diet.
  
  
  METHODS
  Serum cobalamin and the functional markers plasma methylmalonic acid (MMA) and total homocysteine (tHcy) were determined in 173 newborns and their mothers. Forty-five children and mothers were reinvestigated after 6 weeks.
  
  
  RESULTS
  At birth, median (interquartile range) serum cobalamin levels were 245 (175-323) pmol/L in the mothers and 314 (238-468) pmol/L in the newborns. In the neonates, serum cobalamin, but not folate, was inversely associated with MMA and tHcy. Among maternal factors, low serum cobalamin was the strongest predictor of impaired cobalamin function (defined as low cobalamin, high tHcy, or high MMA levels) in the newborns. After 6 weeks, the maternal cobalamin levels had increased (to 421 [271-502] pmol/L), whereas the newborn levels had declined (to 230 [158-287] pmol/L). In the same interval, the infants had a marked increase in plasma MMA (from 0.29 [0.24-0.38] to 0.81 [0.37-1.68] micromol/L). At 6 weeks, parity was a strong predictor of cobalamin status in the infant.
  
  
  CONCLUSIONS
  The cobalamin status in the neonatal period is strongly associated with maternal cobalamin status and parity. A reduction in serum cobalamin and an increase in metabolite levels are consistent with impaired cobalamin function in a significant portion of the infants who were born to healthy, nonvegetarian mothers.
authors.affiliation: LOCUS for Homocysteine and Related Vitamins, University of Bergen, Bergen, Norway. albm@online.no
authors.forename: A L
authors.initials: AL
authors.lastname: Bjørke Monsen
authors.forename: P M
authors.initials: PM
authors.lastname: Ueland
authors.forename: S E
authors.initials: SE
authors.lastname: Vollset
authors.forename: A B
authors.initials: AB
authors.lastname: Guttormsen
authors.forename: T
authors.initials: T
authors.lastname: Markestad
authors.forename: E
authors.initials: E
authors.lastname: Solheim
authors.forename: H
authors.initials: H
authors.lastname: Refsum
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D016015:Logistic Models; D008431:Maternal-Fetal Exchange; D008764:Methylmalonic Acid / Q000097:blood; D010298:Parity; D011247:Pregnancy; D012016:Reference Values; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D015415:Biomarkers; D006710:Homocysteine; D008764:Methylmalonic Acid; D014805:Vitamin B 12