title: Preventing vitamin B12 deficiency in South Asian women of childbearing age: a randomised controlled trial comparing an oral vitamin B12 supplement with B12 dietary advice.
abstract: OBJECTIVE
  To examine the effectiveness, acceptability and sustainability of interventions to reduce vitamin B12 (B12) deficiency in South Asian women before conception.
  
  
  METHODS
  A 6-month randomised controlled trial conducted in Auckland, New Zealand. Participants (62 South Asian women, 18-50 years old) were stratified by dietary practices, then randomised to three treatment groups: B12 Supplement (oral cyanocobalamin 6 μg/day) (n=21), Placebo (n=21), or B12 Dietary Advice (n=20). Primary outcome measures were changes in B12 biomarkers (serum B12 and holotranscobalamin (holoTC)) at 6 months. Dietary B12 intake was estimated from a B12 food-specific frequency questionnaire (B12FFQ). Intention-to-treat analysis was applied using 'last observation carried forward' method. Changes in B12 biomarkers by treatment were compared using analysis of variance. Pearson's correlations tested relationships between dietary B12 intake and B12 biomarkers.
  
  
  RESULTS
  At baseline, 48% of women tested as insufficient or deficient in serum B12 (<222 pmol/l) and 51% as insufficient or deficient in holoTC (<45 pmol/l). B12 status was moderately correlated with dietary B12 intake (r=0.5, 95% confidence interval (CI) (0.3-0.7)) and 44% of women reported insufficient dietary intake (<2.4 μg/day). B12 Supplement was the only treatment group to record a significant increase in B12 biomarkers over 6 months: serum B12 by 30% (95% CI (11-48%)) and holoTC by 42% (12-72%).
  
  
  CONCLUSIONS
  The prevalence of B12 insufficiency among Auckland South Asian women is high and moderately correlated with inadequate intake of foods that contain B12. Cyanocobalamin supplementation (6 μg/day) was associated with improved B12 biomarkers, with a potential to improve preconception B12 status in South Asian women.
authors.affiliation: School of Health Care Practice, Faculty of Health and Environmental Sciences, AUT University, Auckland, New Zealand.
authors.forename: G J
authors.identifier: 000000022397767X
authors.initials: GJ
authors.lastname: Mearns
authors.affiliation: Interdisciplinary Trauma Research Centre, Faculty of Health and Environmental Sciences, AUT University, Auckland, New Zealand.
authors.forename: J
authors.initials: J
authors.lastname: Koziol-McLain
authors.affiliation: Centre for Child Health Research, Faculty of Health and Environmental Sciences, AUT University, Auckland, New Zealand.
authors.forename: V
authors.initials: V
authors.lastname: Obolonkin
authors.affiliation: Centre for Child Health Research, Faculty of Health and Environmental Sciences, AUT University, Auckland, New Zealand.
authors.forename: E C
authors.initials: EC
authors.lastname: Rush
mesh_terms: D000328:Adult; D001208:Asia / Q000208:ethnology; D015415:Biomarkers / Q000097:blood; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D016742:Preconception Care; D015995:Prevalence; D014805:Vitamin B 12 / Q000097:blood / Q000627:therapeutic use*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D014803:Vitamin B Complex / Q000097:blood / Q000627:therapeutic use*; D014930:Women
chemical_list: D015415:Biomarkers; D014803:Vitamin B Complex; D014805:Vitamin B 12
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