title: Calcium and vitamin D3 supplements in calcium and vitamin D3 sufficient early postmenopausal healthy women.
abstract: OBJECTIVE
  To study the calcium homeostasis in healthy, calcium and vitamin D replete early postmenopausal women during oral supplementation with calcium and vitamin D3.
  
  
  METHODS
  A prospective, placebo-controlled, randomised, double-single-blind, 3-week study.
  
  
  METHODS
  Outpatient clinic at Copenhagen University Hospital, Denmark.
  
  
  METHODS
  In all, 17 started, one was excluded. Totally, 16 healthy women, 45-61 y of age (mean 57.3 y) who were at least 4 y after menopause (mean 6.7 y) completed.
  
  
  METHODS
  All underwent three consecutive 7-day study periods. Each began with 4 days of normal diet followed by 3 days treatment of either C: one tablet of 1.250 mg calcium carbonate (ie 500 mg Ca2+ per tablet) twice daily (breakfast and dinner), or CD3: as in C but plus 400 IU vitamin D3 b.i.d., or P (only) placebo tablets b.i.d.
  
  
  RESULTS
  At baseline plasma 25-hydroxycholecalciferol was normal (66+/-22 nmol/l) and the calcium intake without supplements 850 mg/day. In group C, the 24-h urinary calcium increased by 35% (6.9+/-2.0 mmol), vs the placebo group P (5.1+/-1.6 mmol) (P < 0.05). Addition of 800 IU vitamin D3 daily (CD3) did not increase calcium excretion further (6.6+/-2.1 mmol) but decreased plasma 1,25-(OH)2-vitamin D3 by 21% (P < 0.05).
  
  
  CONCLUSIONS
  In this carefully controlled study calcium plus vitamin D3 supplements only had minor influences of uncertain significance on the calcium balance in healthy, calcium and vitamin D sufficient early postmenopausal women.
authors.affiliation: Department of Endocrinology PE, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Tfelt-Hansen
authors.forename: O
authors.initials: O
authors.lastname: Tørring
mesh_terms: D000284:Administration, Oral; D002117:Calcitriol / Q000097:blood; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000378:metabolism* / Q000652:urine; D002762:Cholecalciferol / Q000008:administration & dosage*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004100:Dihydroxycholecalciferols / Q000097:blood; D004311:Double-Blind Method; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D017698:Postmenopause / Q000378:metabolism*; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D002136:Calcium, Dietary; D004100:Dihydroxycholecalciferols; D002762:Cholecalciferol; D002117:Calcitriol