title: Effect of weekly high-dose vitamin D3 supplementation on serum cholecalciferol concentrations in pregnant women.
abstract: Vitamin D status is conventionally defined by the serum concentration of 25-hydroxyvitamin D. However, it has been proposed that the serum cholecalciferol concentration (D3) also determines functional vitamin D sufficiency. The objective of this study was to describe the effect of weekly high-dose vitamin D3 supplementation on inter-dose serum D3 in pregnant women. We conducted a sub-study of a completed randomized double-blind placebo-controlled trial of vitamin D3 (35,000 IU/week) supplementation in late pregnancy (AViDD trial) in Dhaka, Bangladesh. This study included pregnant women enrolled at 26-29 weeks gestation who fully adhered to the prenatal supplement intervention for ≥8 consecutive weeks and for whom serum samples were available for D3 analysis (n=65). Serum D3 was uniformly low at enrolment. Mean D3 increased and was maximal at 1 day after vitamin D dose administration (152.09nmol/L, SD 25.11nmol/L) and remained significantly higher in VitD vs. Pl at 7 days (29.59nmol/L vs. 1.92nmol/L, p=0.007). Daily average of the group mean D3 during the week following dosing was 66.97nmol/L in VitD versus 2.13nmol/L in Pl. In conclusion, serum D3 remained significantly elevated throughout the week following ≥8 consecutive weekly doses of 35,000 IU D3 in pregnant women. However, the clinically significant minimum threshold of serum D3 remains to be established.
authors.affiliation: Centre for Global Child Health and Child Health Evaluative Sciences, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON, Canada.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Dimitris
authors.affiliation: Centre for Global Child Health and Child Health Evaluative Sciences, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, ON, Canada.
authors.forename: Nandita
authors.initials: N
authors.lastname: Perumal
authors.affiliation: Analytical Facility for Bioactive Molecules, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON, Canada.
authors.forename: Hayley A
authors.initials: HA
authors.lastname: Craig-Barnes
authors.affiliation: Analytical Facility for Bioactive Molecules, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Leadley
authors.affiliation: Centre for Child and Adolescent Health, icddr,b, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Mahmud
authors.affiliation: Centre for Child and Adolescent Health, icddr,b, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh; International Center for Maternal and Newborn Health, Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, USA.
authors.forename: Abdullah H
authors.initials: AH
authors.lastname: Baqui
authors.affiliation: Centre for Global Child Health and Child Health Evaluative Sciences, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON, Canada; Department of Paediatrics, University of Toronto and Hospital for Sick Children, 686 Bay Street, Toronto, ON, Canada. Electronic address: daniel.roth@sickkids.ca.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Roth
mesh_terms: D000328:Adult; D002762:Cholecalciferol / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D011247:Pregnancy / Q000097:blood*; D014815:Vitamins / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*; D055815:Young Adult
chemical_list: D014815:Vitamins; D002762:Cholecalciferol
keywords: Bangladesh; Cholecalciferol; Pharmacokinetics; Pregnancy; Vitamin D