title: Effects of Vitamin D3 Supplementation on Lean Mass, Muscle Strength, and Bone Mineral Density During Weight Loss: A Double-Blind Randomized Controlled Trial.
abstract: OBJECTIVE
  To compare the effects of 12 months of vitamin D3 supplementation with that placebo on lean mass, bone mineral density (BMD), and muscle strength in overweight or obese postmenopausal women completing a structured weight-loss program.
  
  
  METHODS
  Double-blind, placebo-controlled randomized clinical trial.
  
  
  METHODS
  Fred Hutchinson Cancer Research Center, Seattle, Washington.
  
  
  METHODS
  Postmenopausal women aged 50 to 75 with a body mass index (BMI) of 25 kg/m(2) or greater and a serum 25-hydroxyvitamin D (25(OH)D) concentration between 10.0 and 32.0 ng/mL (insufficient) (N = 218).
  
  
  METHODS
  Oral vitamin D3 2,000 IU/d or placebo in combination with a lifestyle-based weight loss intervention consisting of a reduction of 500 kcal to 1,000 kcal per day and 225 min/wk of moderate- to vigorous-intensity aerobic exercise.
  
  
  METHODS
  Serum 25(OH)D, body composition, and muscle strength were measured before randomization (baseline) and at 12 months. Mean changes of the groups were compared (intention to treat) using generalized estimating equations.
  
  
  RESULTS
  Change in 25(OH)D was significantly different between the vitamin D and placebo groups at 12 months (13.6 ng/mL vs -1.3 ng/mL, P < .001), but no differences in change in lean mass (-0.8 kg vs -1.1 kg, P = .53) or BMD of the spine (-0.01 g/cm(2) vs 0.0 g/cm(2) , P = .82) or right femoral neck (both -0.01 g/cm(2) , P = .49) were detected between the groups. Leg strength decreased in the vitamin D group but not in the placebo group (-2.6 pounds vs 1.8 pounds, P = .03). In women randomized to vitamin D, achieving repletion (25(OH)D ≥ 32 ng/mL) did not alter results.
  
  
  CONCLUSIONS
  Vitamin D3 supplementation during weight-loss decreased leg strength but did not alter changes in lean mass or BMD in postmenopausal women with vitamin D insufficiency.
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Mason
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Jean D
authors.initials: JD
authors.lastname: Tapsoba
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Catherine
authors.initials: C
authors.lastname: Duggan
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Imayama
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.|School of Public Health, University of Washington, Seattle, Washington.
authors.forename: Ching-Yun
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.|Department of Medicine, University of Washington, Seattle, Washington.
authors.forename: Larissa
authors.initials: L
authors.lastname: Korde
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.|School of Public Health, University of Washington, Seattle, Washington.
authors.forename: Anne
authors.initials: A
authors.lastname: McTiernan
mesh_terms: D000368:Aged; D001823:Body Composition; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects*; D002762:Cholecalciferol / Q000008:administration & dosage*; D004311:Double-Blind Method; D015444:Exercise; D005260:Female; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects*; D017698:Postmenopause; D014861:Washington; D015431:Weight Loss / Q000187:drug effects*
chemical_list: D002762:Cholecalciferol
keywords: 25-hydroxyvitamin D; caloric restriction; exercise; obesity; strength