title: Bioavailability of vitamin D3 in non-oily capsules: the role of formulated compounds and implications for intermittent replacement.
abstract: OBJECTIVE
  To evaluate the bioavailability of vitamin D in capsules as compared with oily drops in nuns living in a closed community with very low sun exposure.
  
  
  METHODS
  A randomized, 2 x 2 crossover, open clinical trial was conducted, with 18 nuns aged between 20 and 75 years. Samples were collected in the fasting state and at 4, 8, 12 and 24 hours following the administration of capsules and oily drops (both containing vitamin D3 66,000 UI plus vitamin A 13,200 UI) to determine serum 25 hydroxyvitamin D concentrations (25OHD), at baseline and 90 days after. The evaluation was based on the maximum concentration (Cmax) and area under the curve (AUC0-24).
  
  
  RESULTS
  The capsule formulation presented Cmax and AUC0-24, 5.78% and 0.76%, respectively, greater than the oily drops formulation.
  
  
  CONCLUSIONS
  Both formulations were within the limits for a bioequivalence study, namely C-90% for Cmax and AUC0-24, and the drugs were considered bioequivalent.
authors.affiliation: Hospital Agamenon Magalhães, Universidade de Pernambuco, Recife, PE, Brasil. csamarques@hotmail.com <csamarques@hotmail.com>
authors.forename: Iara Maria Gomes
authors.initials: IM
authors.lastname: Coelho
authors.forename: Luena Dias de
authors.initials: LD
authors.lastname: Andrade
authors.forename: Lunnara
authors.initials: L
authors.lastname: Saldanha
authors.forename: Erik Trovão
authors.initials: ET
authors.lastname: Diniz
authors.forename: Luiz
authors.initials: L
authors.lastname: Griz
authors.forename: Francisco
authors.initials: F
authors.lastname: Bandeira
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001682:Biological Availability; D002214:Capsules; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D013810:Therapeutic Equivalency; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000517:prevention & control; D055815:Young Adult
chemical_list: D002214:Capsules; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D