title: Maternal vitamin D status and infant outcomes in rural Vietnam: a prospective cohort study.
abstract: OBJECTIVE
  Vitamin D deficiency affects 1 billion people globally. It has an important role in bone homeostasis, brain development and modulation of the immune system and yet the impact of antenatal vitamin D deficiency on infant outcomes is poorly understood. We assessed the association of 25- hydroxyvitamin D levels (25-OHD) in late pregnancy and early infant growth and developmental outcomes in rural Vietnam.
  
  
  METHODS
  A prospective cohort study of 960 women who had previously participated in a double-blind cluster randomized controlled trial of antenatal micronutrient supplementation in rural Vietnam was undertaken. Maternal 25-OHD concentration was measured at 32 weeks gestation, and infants were followed until 6 months of age. Main outcome measures were cognitive, motor, socio-emotional and language scores using the Bayley Scales of Infant Development, 3rd edition, and infant length-for-age z scores at 6 months of age.
  
  
  RESULTS
  60% (582/960) of women had 25-OHD levels <75 nmol/L at 32 weeks gestation. Infants born to women with 25-OHD deficiency (<37.5 nmol/L) had reduced developmental language scores compared to those born to women who were vitamin D replete (≥75 nmol/L) (Mean Difference (MD) -3.48, 95% Confidence Interval (CI) -5.67 to -1.28). For every 25 nmol increase in 25-OHD concentration in late pregnancy, infant length-for-age z scores at 6 months of age decreased by 0.08 (95% CI -0.15 to -0.02).
  
  
  CONCLUSIONS
  Low maternal 25- hydroxyvitamin D levels during late pregnancy are of concern in rural Vietnam, and are associated with reduced language developmental outcomes at 6 months of age. Our findings strengthen the evidence for giving vitamin D supplementation during pregnancy.
authors: Department of Medicine, Melbourne Academic Centre, University of Melbourne at the Doherty Institute, Parkville, Victoria, Australia.
authors: Sarah
authors: S
authors: Hanieh
authors: Research and Training Centre for Community Development (RTCCD), Hanoi, Vietnam.
authors: Tran T
authors: TT
authors: Ha
authors: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Victoria, Australia.
authors: Julie A
authors: JA
authors: Simpson
authors: Research and Training Centre for Community Development (RTCCD), Hanoi, Vietnam.
authors: Tran T
authors: TT
authors: Thuy
authors: Provincial Centre of Preventive Medicine, Hanam, Hanam Province, Vietnam.
authors: Nguyen C
authors: NC
authors: Khuong
authors: Provincial Centre of Preventive Medicine, Hanam, Hanam Province, Vietnam.
authors: Dang D
authors: DD
authors: Thoang
authors: Research and Training Centre for Community Development (RTCCD), Hanoi, Vietnam; The Jean Hailes Research Unit, School of Public Health and Preventive Medicine, Monash University, Clayton, Victoria, Australia.
authors: Thach D
authors: TD
authors: Tran
authors: Research and Training Centre for Community Development (RTCCD), Hanoi, Vietnam.
authors: Tran
authors: T
authors: Tuan
authors: The Jean Hailes Research Unit, School of Public Health and Preventive Medicine, Monash University, Clayton, Victoria, Australia.
authors: Jane
authors: J
authors: Fisher
authors: Department of Medicine, Melbourne Academic Centre, University of Melbourne at the Doherty Institute, Parkville, Victoria, Australia; The Victorian Infectious Diseases Service, Royal Melbourne Hospital, Parkville, Victoria, Australia.
authors: Beverley-Ann
authors: BA
authors: Biggs
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000328:Adult; D002657:Child Development; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012424:Rural Population; D014744:Vietnam; D014807:Vitamin D / Q000008:administration & dosage / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2