title: Calcium plus vitamin D supplementation and the risk of postmenopausal weight gain.
abstract: BACKGROUND
  Obesity in the United States has increased significantly during the past several decades. The role of calcium in the maintenance of a healthy body weight remains controversial.
  
  
  METHODS
  A randomized, double-blinded, placebo-controlled trial was performed with 36 282 postmenopausal women, aged 50 to 79 years, who were already enrolled in the dietary modification and/or hormone therapy arms of the Women's Health Initiative clinical trial. Women were randomized at their first or second annual visit to receive a dose of 1000 mg of elemental calcium plus 400 IU of cholecalciferol (vitamin D) or placebo daily. Change in body weight was ascertained annually for an average of 7 years.
  
  
  RESULTS
  Women receiving calcium plus cholecalciferol supplements vs women receiving placebo had a minimal but consistent favorable difference in weight change (mean difference, -0.13 kg; 95% confidence interval, -0.21 to -0.05; P = .001). After 3 years of follow-up, women with daily calcium intakes less than 1200 mg at baseline who were randomized to supplements were 11% less likely to experience small weight gains (1-3 kg) and 11% less likely to gain more moderate amounts of weight (>3 kg) (P for interaction for baseline calcium intake = .008).
  
  
  CONCLUSIONS
  Calcium plus cholecalciferol supplementation has a small effect on the prevention of weight gain, which was observed primarily in women who reported inadequate calcium intakes.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00000611.
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA 94612, USA. bjc@dor.kaiser.org
authors.forename: Bette
authors.initials: B
authors.lastname: Caan
authors.forename: Marian
authors.initials: M
authors.lastname: Neuhouser
authors.forename: Aaron
authors.initials: A
authors.lastname: Aragaki
authors.forename: Cora Beth
authors.initials: CB
authors.lastname: Lewis
authors.forename: Rebecca
authors.initials: R
authors.lastname: Jackson
authors.forename: Meryl S
authors.initials: MS
authors.lastname: LeBoff
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
authors.forename: Lynda
authors.initials: L
authors.lastname: Powell
authors.forename: Gabriel
authors.initials: G
authors.lastname: Uwaifo
authors.forename: Evelyn
authors.initials: E
authors.lastname: Whitlock
authors.forename: Judy
authors.initials: J
authors.lastname: Wylie-Rosett
authors.forename: Andrea
authors.initials: A
authors.lastname: LaCroix
mesh_terms: D000368:Aged; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D002136:Calcium, Dietary / Q000008:administration & dosage*; D002762:Cholecalciferol / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology*; D013997:Time Factors; D014815:Vitamins / Q000008:administration & dosage*; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D050071:Bone Density Conservation Agents; D002136:Calcium, Dietary; D014815:Vitamins; D002762:Cholecalciferol