Late Breaking News
Vitamin D No Help for Knee Osteoarthritis
BOSTON - Vitamin D supplementation did not result in a significant difference in knee pain or cartilage volume loss in patients with symptomatic knee osteoarthritis compared to a placebo group, according to a study from Tufts Medical Center in Boston.1
The report, partly funded by the Houston Veterans Affairs Health Services Research and Development Service and based on a two-year randomized trial, was published in the Journal of the American Medical Association.
“Knee osteoarthritis (OA) is a common age-related musculoskeletal disorder that has significant functional impact and has considerable societal costs through work loss, early retirement and arthroplasty. Despite its impact, there are no medical treatments established to influence the course of the disease,” according to background information in the article. “Some studies have suggested that vitamin D may protect against structural progression.”
The two-year randomized, placebo-controlled clinical trial included 146 participants — 61% female with an average age of 62 — March 2006 and June 2009. Participants were randomized to receive either placebo or oral cholecalciferol, 2,000 IU/day, with dose escalation to increase serum levels to more than 36 ng/mL.
Knee pain severity, gauged using the Western Ontario and McMaster Universities [WOMAC] pain scale, and cartilage volume loss measured by magnetic resonance imaging were the primary outcomes for the study.
Secondary outcomes included physical function, knee function, cartilage thickness, bone marrow lesions and radiographic joint space width.
Over the course of the study, serum 25-hydroxyvitamin D levels increased by an average 16.1 ng/mL in the treatment group and by an average 2.1 ng/mL in the placebo group.
Based on the WOMAC scale, 0-20, with 0 designating no pain and 20 designating extreme pain, knee pain initially was slightly worse in the treatment group (average, 6.9) than in the placebo group (average, 5.8), as was knee function.
Researchers found that knee pain decreased an average -2.31 in the treatment group and -1.46 in the placebo group but did not deem that significant. Cartilage volume decreased in both groups by about 4%, and there were no differences in any of the secondary clinical end points, according to the study.
Study authors noted that “the overall data suggest that vitamin D supplementation at a dose sufficient to elevate 25-hydroxyvitamin D levels to more than 36 ng/mL does not have major effects on clinical or structural outcomes in knee OA, at least in a U.S. sample.”
1. McAlindon T, LaValley M, Schneider E, Nuite M, Lee JY, Price LL, Lo G, Dawson-Hughes B. Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial. JAMA. 2013 Jan 9;309(2):155-62. doi:10.1001/jama.2012.164487. PubMed PMID: 23299607.