title: Maternal vitamin D status affects bone growth in early childhood--a prospective cohort study.
abstract: In this prospective study, 87 children were followed up from birth to 14 months with data on maternal vitamin D status during the pregnancy. Postnatal vitamin D supplementation improved vitamin D status but only partly eliminated the differences in bone variables induced by maternal vitamin D status during the fetal period.
  
  
  BACKGROUND
  Intrauterine nutritional deficits may have permanent consequences despite improved nutritional status postnatally. We evaluated the role of prenatal and postnatal vitamin D status on bone parameters in early infancy.
  
  
  METHODS
  Eighty-seven children were followed from birth to 14 months. Background data were collected with a questionnaire and a 3-day food record. At 14 months bone variables were measured with peripheral computed tomography (pQCT) from the left tibia. Serum 25-OHD and bone turnover markers were determined. Findings were compared with maternal vitamin D status during pregnancy.
  
  
  RESULTS
  The children were divided into two groups based on vitamin D status during pregnancy. Despite discrepant S-25-OHD at baseline (median 36.3 vs. 52.5 nmol/l, p < 0.001), the values at 14 months were similar (63 vs. 66 nmol/l, p = 0.58) in Low D and High D. Serum 25-OHD increased more in Low D (p < 0.001) despite similar total intake of vitamin D (mean 12.3 μg/day). In Low D, tibial bone mineral content (BMC) was lower at birth but BMC gain was greater (multivariate analysis of variance [MANOVA]; p = 0.032) resulting in similar BMC at 14 months in the two groups. In High D, tibial total bone cross-sectional area was higher at baseline; the difference persisted at 14 months (MANOVA; p = 0.068). Bone mineral density (BMD) and ΔBMD were similar in the two groups.
  
  
  CONCLUSIONS
  Postnatal vitamin D supplementation improved vitamin D status but only partly eliminated the differences in bone variables induced by maternal vitamin D status during the fetal period. Further attention should be paid to improving vitamin D status during pregnancy.
authors.affiliation: Hospital for Children and Adolescents, Helsinki University Central Hospital, Tukholmankatu 2C, PO Box 705, 00029 Helsinki, Finland. heli.viljakainen@helsinki.fi
authors.forename: H T
authors.initials: HT
authors.lastname: Viljakainen
authors.forename: T
authors.initials: T
authors.lastname: Korhonen
authors.forename: T
authors.initials: T
authors.lastname: Hytinantti
authors.forename: E K A
authors.initials: EK
authors.lastname: Laitinen
authors.forename: S
authors.initials: S
authors.lastname: Andersson
authors.forename: O
authors.initials: O
authors.lastname: Mäkitie
authors.forename: C
authors.initials: C
authors.lastname: Lamberg-Allardt
mesh_terms: D015519:Bone Density; D001846:Bone Development / Q000187:drug effects*; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011446:Prospective Studies; D013977:Tibia / Q000000981:diagnostic imaging / Q000254:growth & development*; D014057:Tomography, X-Ray Computed; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D