title: Maternal and infant vitamin D status during the first 9 months of infant life-a cohort study.
abstract: OBJECTIVE
  The objective of this study was to assess vitamin D status and possible consequences of low plasma 25-hydroxyvitamin D (25OHD) levels in a population of healthy mothers and their infants.
  
  
  METHODS
  A total of 107 women aged 24-41 years gave birth to 108 infants. They were followed up three times during 9 months.
  
  
  RESULTS
  Cord blood 25OHD level (43.3 ± 20.4  nmol/l) on average was 62 ± 16% of maternal levels (73.3 ± 30.7  nmol/l), measured 1-2 weeks postpartum. Cord blood 25OHD correlated positively with maternal 25OHD levels (r=0.83, P<0.001). At birth, 23% of mothers and 61% of infants had 25OHD <50  nmol/l. Vitamin D deficiency (25OHD<25  nmol/l) was present in 66% of the children born by mothers with 25OHD levels below 50  nmol/l (P<0.01), whereas only one child was born with deficiency among mothers with 25OHD >50  nmol/l. During follow-up, most of the children (>85%) had 25OHD levels >50  nmol/l, which most likely was attributable to the use of supplements, as more than 95% of the children were given daily vitamin D supplements of 10  μg of vitamin D.Cord blood parathyroid hormone levels were very low (median 0.21; interquartile range 0.11-0.33  pmol/l), with increasing levels (P<0.01) reaching 3.08 (2.67-3.92  pmol/l) at the last visit. Vitamin D levels were not associated with anthropometric indices of the newborn infant or their growth during follow-up.
  
  
  CONCLUSIONS
  Vitamin D deficiency is widespread in newborn. Maternal 25OHD levels above 50  nmol/l are needed to prevent vitamin D deficiency among newborn.
authors.affiliation: Department of Endocrinology and Internal Medicine (MEA), Aarhus University Hospital, Aarhus, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Við Streym
authors.forename: U
authors.initials: U
authors.lastname: Kristine Moller
authors.forename: L
authors.initials: L
authors.lastname: Rejnmark
authors.forename: L
authors.initials: L
authors.lastname: Heickendorff
authors.forename: L
authors.initials: L
authors.lastname: Mosekilde
authors.forename: P
authors.initials: P
authors.lastname: Vestergaard
mesh_terms: D000328:Adult; D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D005312:Fetal Blood; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood / Q000453:epidemiology*; D008297:Male; D009035:Mothers; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D