Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial.

JAMA

Jan 2013

DOI: 10.1001/jama.2012.164487

Citations:266

Influential Citations:9

Interventional (Human) Studies

Enhanced Details

Methods

Single-center, randomized, placebo-controlled, double-blind trial at Tufts Medical Center; 146 participants with symptomatic knee osteoarthritis; mean age 62.4 ± 8.5 years; eligibility: age ≥45, radiographic Kellgren–Lawrence grade ≥2 with symptomatic knee OA.

Intervention

Oral cholecalciferol (Vitamin D3) 2,000 IU daily, with 2,000 IU increments at 4, 8, and 12 months to reach 25OHD 36–100 ng/mL; duration 24 months; no calcium supplementation.

Results

Vitamin D3 supplementation raised 25OHD to 38.5 ng/mL at 24 months (vs 24.7 ng/mL with placebo); 61.3% reached ≥36 ng/mL by month 24 in the vitamin D group vs 8.3% in placebo. Knee pain declined by ~2 points in both groups; ~4% cartilage volume loss over 2 years in both groups; no significant differences in MRI cartilage measures, bone marrow lesions, radiographic joint space width, or other clinical outcomes. Adverse events were similar between groups; no hypercalcemia observed. Authors conclude that elevating 25OHD above 36 ng/mL with this regimen does not meaningfully affect knee OA symptoms or progression in this US cohort.

Limitations

Possible type II error due to smaller-than-expected cartilage loss; single-center, 2-year duration; inclusion of Kellgren-Lawrence grade 4 knees may limit generalizability; MRI analysis focused on the index knee compartment; p-values not adjusted for multiple comparisons.

Abstract

IMPORTANCE 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. DESIGN, SETTING, AND PATIENTS 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. INTERVENTION 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. MAIN OUTCOME MEASURES 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. CONCLUSION AND RELEVANCE 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. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00306774. show less