title: High rate of maternal vitamin B12 deficiency nearly a decade after Canadian folic acid flour fortification.
abstract: Vitamin B12 deficiency may be an independent risk factor for neural tube defects (NTD). We determined the prevalence of biochemical B12 deficiency (<125 pmol/l) among 10 622 Ontarian women aged 15-46 years who underwent concomitant testing of serum bhCG and B12 9 years after the implementation of Canadian folic acid flour fortification. The overall prevalence of biochemical B12 deficiency was 7.4%. Relative to non-pregnant women, the adjusted odds ratio (95% confidence interval) of biochemical B12 deficiency was 0.78 (0.60-1.0) among women pregnant 28 days gestation or less and was 1.4 (1.1-1.8) after 28 days gestation. About 1 in 20 women may be deficient in B12 in early pregnancy. The impact on maternal and fetal well-being, including preventable NTD, should be considered.
authors.affiliation: Department of Medicine, St Michael's Hospital, University of Toronto, 30 Bond Street, Toronto, Ontario, Canada. rayj@smh.toronto.on.ca
authors.forename: J G
authors.initials: JG
authors.lastname: Ray
authors.forename: J
authors.initials: J
authors.lastname: Goodman
authors.forename: P R A
authors.initials: PR
authors.lastname: O'Mahoney
authors.forename: M M
authors.initials: MM
authors.lastname: Mamdani
authors.forename: D
authors.initials: D
authors.lastname: Jiang
mesh_terms: D000293:Adolescent; D000328:Adult; D002170:Canada / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood; D005494:Folic Acid Deficiency / Q000097:blood / Q000453:epidemiology*; D005500:Follow-Up Studies; D005527:Food, Fortified; D006801:Humans; D007231:Infant, Newborn; D008875:Middle Aged; D009436:Neural Tube Defects / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000517:prevention & control; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology*; D011256:Pregnancy Outcome; D018570:Risk Assessment; D016216:Ultrasonography, Prenatal; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D005492:Folic Acid