title: Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial.
abstract: OBJECTIVE
  Knee osteoarthritis (OA), a disorder of cartilage and periarticular bone, is a public health problem without effective medical treatments. Some studies have suggested that vitamin D may protect against structural progression.
  
  
  OBJECTIVE
  To determine whether vitamin D supplementation reduces symptom and structural progression of knee OA.
  
  
  METHODS
  A 2-year randomized, placebo-controlled, double-blind, clinical trial involving 146 participants with symptomatic knee OA (mean age, 62.4 years [SD, 8.5]; 57 women [61%], 115 white race [79%]). Patients were enrolled at Tufts Medical Center in Boston between March 2006 and June 2009.
  
  
  METHODS
  Participants were randomized to receive either placebo or oral cholecalciferol, 2000 IU/d, with dose escalation to elevate serum levels to more than 36 ng/mL.
  
  
  METHODS
  Primary outcomes were knee pain severity (Western Ontario and McMaster Universities [WOMAC] pain scale, 0-20: 0, no pain; 20, extreme pain), and cartilage volume loss measured by magnetic resonance imaging. Secondary end points included physical function, knee function (WOMAC function scale, 0-68: 0, no difficulty; 68, extreme difficulty), cartilage thickness, bone marrow lesions, and radiographic joint space width.
  
  
  RESULTS
  Eighty-five percent of the participants completed the study. Serum 25-hydroxyvitamin D levels increased by a mean 16.1 ng/mL (95% CI, 13.7 to 18.6) in the treatment group and by a mean 2.1 mg/mL (95% CI, 0.5 to 3.7) (P < .001) in the placebo group. Baseline knee pain was slightly worse in the treatment group (mean, 6.9; 95% CI, 6.0 to 7.7) than in the placebo group (mean, 5.8; 95% CI, 5.0 to 6.6) (P = .08). Baseline knee function was significantly worse in the treatment group (mean, 22.7; 95% CI, 19.8 to 25.6) than in the placebo group (mean, 18.5; 95% CI, 15.8 to 21.2) (P = .04). Knee pain decreased in both groups by a mean -2.31 (95% CI, -3.24 to -1.38) in the treatment group and -1.46 (95% CI, -2.33 to -0.60) in the placebo group, with no significant differences at any time. The percentage of cartilage volume decreased by the same extent in both groups (mean, -4.30; 95% CI, -5.48 to -3.12 vs mean, -4.25; 95% CI, -6.12 to -2.39) (P = .96). There were no differences in any of the secondary clinical end points.
  
  
  CONCLUSIONS
  Vitamin D supplementation for 2 years at a dose sufficient to elevate 25-hydroxyvitamin D plasma levels to higher than 36 ng/mL, when compared with placebo, did not reduce knee pain or cartilage volume loss in patients with symptomatic knee OA.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00306774.
authors.affiliation: Division of Rheumatology, Tufts Medical Center, Box 406, 800 Washington St, Boston, MA 02111, USA. tmcalindon@tuftsmedicalcenter.org
authors.forename: Timothy
authors.initials: T
authors.lastname: McAlindon
authors.forename: Michael
authors.initials: M
authors.lastname: LaValley
authors.forename: Erica
authors.initials: E
authors.lastname: Schneider
authors.forename: Melynn
authors.initials: M
authors.lastname: Nuite
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Lee
authors.forename: Lori Lyn
authors.initials: LL
authors.lastname: Price
authors.forename: Grace
authors.initials: G
authors.lastname: Lo
authors.forename: Bess
authors.initials: B
authors.lastname: Dawson-Hughes
mesh_terms: D000368:Aged; D002356:Cartilage / Q000473:pathology*; D019587:Dietary Supplements; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000188:drug therapy* / Q000473:pathology; D010146:Pain / Q000209:etiology* / Q000517:prevention & control; D016896:Treatment Outcome; D014807:Vitamin D / Q000627:therapeutic use*; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D014807:Vitamin D