title: Short-term effect of bedtime consumption of fermented milk supplemented with calcium, inulin-type fructans and caseinphosphopeptides on bone metabolism in healthy, postmenopausal women.
abstract: BACKGROUND
  Milk products are good sources of calcium and their consumption may reduce bone resorption and thus contribute to prevent bone loss.
  
  
  OBJECTIVE
  We tested the hypothesis that bedtime consumption of fermented milk supplemented with calcium inhibits the nocturnally enhanced bone resorption more markedly than fermented milk alone, and postulated that this effect was most pronounced when calcium absorption enhancers were added.
  
  
  METHODS
  In a controlled, parallel, double-blind intervention study over 2 weeks we investigated the short-term effects of two fermented milks supplemented with calcium from milk minerals (f-milk + Ca, n = 28) or calcium from milk minerals, inulin-type fructans and caseinphosphopeptides (f-milk + Ca + ITF + CPP; n = 29) on calcium and bone metabolism in healthy, postmenopausal women, and compared them with the effect of a fermented control milk without supplements (f-milk, n = 28). At bedtime 175 ml/d of either test milk was consumed. Fasting blood samples and 48 h-urine were collected at baseline and at the end of the intervention. Urine was divided into a pooled daytime and nighttime fraction. Multifactorial ANOVA was performed.
  
  
  RESULTS
  Fermented milk independent of a supplement (n = 85) reduced the nocturnal excretion of deoxypyridinoline, a marker of bone resorption, from 11.73 +/- 0.54 before to 9.57 +/- 0.54 micromol/mol creatinine at the end of the intervention (P = 0.005). No effect was seen in the daytime fraction. Differences between the three milks (n = 28 resp. 29) were not significant. Fermented milk reduced bone alkaline phosphatase, a marker of bone formation, from 25.03 +/- 2.08 to 18.96 +/- 2.08 U/l, with no difference between these groups either. Fermented milk increased the nocturnal but not daytime urinary excretion of calcium and phosphorus. The effects on calcium and phosphorus excretion were mainly due to the group supplemented with Ca + ITF + CPP.
  
  
  CONCLUSIONS
  Bedtime consumption of fermented milk reduced the nocturnal bone resorption by decelerating its turnover. Supplemented calcium from milk mineral had no additional effect unless the absorption enhancers ITF + CPP were added. A stimulated intestinal calcium absorption may be assumed, since urinary calcium excretion increased at a constant bone resorption.
authors.affiliation: Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut (MRI), Federal Research Institute of Nutrition and Food, Hermann Weigmann Strasse 1, 24103, Kiel, Germany.
authors.forename: Berit
authors.initials: B
authors.lastname: Adolphi
authors.forename: Katharina E
authors.initials: KE
authors.lastname: Scholz-Ahrens
authors.forename: Michael
authors.initials: M
authors.lastname: de Vrese
authors.forename: Yahya
authors.initials: Y
authors.lastname: Açil
authors.forename: Christiane
authors.initials: C
authors.lastname: Laue
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schrezenmeir
mesh_terms: D000368:Aged; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000097:blood / Q000652:urine; D002136:Calcium, Dietary / Q000008:administration & dosage*; D002364:Caseins / Q000008:administration & dosage*; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine; D043302:Cultured Milk Products; D015930:Diet Records; D004311:Double-Blind Method; D005247:Feeding Behavior; D005260:Female; D005527:Food, Fortified; D005630:Fructans / Q000008:administration & dosage*; D006801:Humans; D007444:Inulin; D008875:Middle Aged; D010748:Phosphopeptides / Q000008:administration & dosage*; D010758:Phosphorus / Q000097:blood / Q000652:urine; D017698:Postmenopause; D011795:Surveys and Questionnaires
chemical_list: D002136:Calcium, Dietary; D002364:Caseins; D005630:Fructans; D010748:Phosphopeptides; D010758:Phosphorus; D007444:Inulin; D003404:Creatinine; D002118:Calcium