title: Randomized controlled trial (RCT) of vitamin D supplementation in pregnancy in a population with endemic vitamin D deficiency.
abstract: BACKGROUND
  Vitamin D (vD) deficiency in pregnancy is a global health problem and the amount of vD supplementation to prevent vD deficiency is controversial.
  
  
  OBJECTIVE
  The objective of the study was to determine effectiveness and safety of prenatal 2000 IU and 4000 IU/d compared with 400 IU/d vD3 supplementation in a randomized controlled trial in population in which vD deficiency is endemic.
  
  
  METHODS
  Arab women were randomized at 12-16 weeks of gestation to 400, 2000, and 4000 IU/d vD3, which were continued to delivery. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured during pregnancy and at delivery. The primary outcome was the maternal and cord blood 25(OH)D, and the secondary outcomes were the achievement of sufficient serum 25(OH)D of 32 ng/mL or greater (≥80 nmol/L) at delivery.
  
  
  METHODS
  The locations were primary care and tertiary perinatal care centers.
  
  
  RESULTS
  Of 192 enrolled, 162 (84%) continued to delivery. Mean serum 25(OH)D of 8.2 ng/mL (20.5 nmol/L) at enrollment was low. Mean serum 25(OH)D concentrations at delivery and in cord blood were significantly higher in the 2000 and 4000 IU than the 400 IU/d group (P < .001) and was highest in the 4000 IU/d group. The percent who achieved 25(OH)D greater than 32 ng/mL and greater than 20 ng/mL concentrations in mothers and infants was highest in 4000 IU/d group. Safety measurements were similar by group and no adverse event related to vD supplementation.
  
  
  CONCLUSIONS
  Vitamin D supplementation of 2000 and 4000 IU/d appeared safe in pregnancy, and 4000 IU/d was most effective in optimizing serum 25(OH)D concentrations in mothers and their infants. These findings could apply to other populations in which vD deficiency is endemic.
authors.affiliation: Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 2048, Cincinnati, Ohio 45229-3026, USA. adekunle.dawodu@cchmc.org
authors.forename: Adekunle
authors.initials: A
authors.lastname: Dawodu
authors.forename: Hussein F
authors.initials: HF
authors.lastname: Saadi
authors.forename: Gharid
authors.initials: G
authors.lastname: Bekdache
authors.forename: Yasin
authors.initials: Y
authors.lastname: Javed
authors.forename: Mekibib
authors.initials: M
authors.lastname: Altaye
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Hollis
mesh_terms: D000328:Adult; D002118:Calcium / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D017063:Outcome Assessment, Health Care; D010281:Parathyroid Hormone / Q000097:blood; D011247:Pregnancy; D014807:Vitamin D / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium