title: Pharmacokinetics and pharmacodynamics of calcium-vitamin D(3) chewable tablets: a single-blind, multiple-dose study in postmenopausal women.
abstract: OBJECTIVE
  The objective of this study is to investigate the effect of a newly developed calcium carbonate-vitamin D₃ chewable tablet formulation (600 mg of calcium + 400 IU of vitamin D₃) on serum/urine calcium and serum parathyroid hormone (PTH) as measures of intestinal calcium absorption compared to a placebo.
  
  
  METHODS
  This is a subject-blind, sequential study in 24 healthy postmenopausal women. Each subject received two placebo tablets once daily for 3 days (days -3 to -1) immediately followed by two calcium-vitamin D₃ tablets (test) during the subsequent 3 days (days 1-3). Serial blood sampling and 24-h urine collection took place on days -1 and 3. The subjects fasted until 6 h post-dosing. Total urinary calcium excretion (Ae(0-24 h)) and AUC(0-6 h) for serum calcium were the primary outcome variables and were compared between treatments using a paired sample t-test.
  
  
  RESULTS
  Ae(0-24 h) increased by 42% (uncorrected, p = 0.0001) and 30% (creatinine-corrected, p = 0.0001), after intake, compared with the placebo; serum calcium exposure (AUC(0-6 h)) was also, statistically, significantly greater. PTH, in serum, decreased by 28% (AUC(0-6 h), p = 0.0001) and 14% (AUC(0-24 h), p = 0.0009) when compared with the placebo.
  
  
  CONCLUSIONS
  Daily intake of 1200 mg of calcium and 800 IU of vitamin D₃, with a new chewable tablet, resulted in increased intestinal calcium absorption compared to the results from the placebo as confirmed by direct and indirect pharmacokinetic/pharmacodynamic measures.
authors.affiliation: Institute for Clinical Pharmacology, Medical Faculty, Technical University, Fiedlerstrasse 27, D 01307 Dresden, Germany. Edgar.Mueller@tu-dresden.de
authors.forename: Edgar A
authors.initials: EA
authors.lastname: Mueller
authors.forename: Michael
authors.initials: M
authors.lastname: Seiberling
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Kirch
authors.forename: Adrian
authors.initials: A
authors.lastname: Frentzel
authors.forename: Sonja
authors.initials: S
authors.lastname: Trapp
mesh_terms: D000368:Aged; D002118:Calcium / Q000097:blood* / Q000652:urine*; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002762:Cholecalciferol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D017698:Postmenopause; D016037:Single-Blind Method; D013607:Tablets
chemical_list: D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D013607:Tablets; D002762:Cholecalciferol; D002118:Calcium