Vitamin D does not improve radiological or clinical outcomes for patients with knee OA

Study Type: Randomized Trial
OE Level of Evidence: 2
Journal Level of Evidence: N/A
474 patients with Kellgren-Lawrence grade II-III knee osteoarthritis were included in a 3-year, double-blind, RCT to evaluate the effect of vitamin D supplementation on the rate of radiographic disease progression. Compared to a placebo group, patients treated with vitamin D supplementation did not demonstrate a slower rate of joint space narrowing (JSN) on radiographs over the 3-year follow-up. There were also Please login to view the rest of this report. Please login to view the rest of this report.
Funding: Non-Industry funded
Sponsor: Arthritis Research Campaign (now Arthritis Research UK, grant number K0576); National Institute for Health Research (NIHR) Musculoskeletal Biomedical Research Unit, University of Oxford (grant number HFRWGQ00 task HF00.EA BRU)
Conflicts: Consultant
Why was this study needed now?
Vitamin D is involved in a number of important biological functions in bone, cartilage, and muscle. Some evidence suggests that low dietary intake of vitamin D and vitamin D deficiency are associated with increased radiological progression of knee osteoarthritis (OA). To date, randomized controlled trials have been unable to provide a definitive conclusion on the role of vitamin D supplementation in the management of knee OA.
What was the principal research question?
Does vitamin D supplementation reduce the rate of radiographic progression of knee OA over a 3-year period?
Population: 474 patients, aged >50 years, with radiological evidence of Kellgren-Lawrence (K-L) grade 2-3 medial compartment knee osteoarthritis, and symptomatic pain for the majority of the previous month.
Intervention: Vitamin D group: Patients received 800 IU of oral cholecalciferol daily (n=237; 141 with radiographs at 3 years) (Mean age: 64+/-8)
Comparison: Control group: Patients received oral placebo daily (n=237; 150 with radiographs at 3 years) (Mean age: 64+/-8)
Outcomes: The primary outcome was radiologic progression of knee OA in the medial joint compartment, measured by the rate of joint space narrowing (JSN, mm/year). Secondary outcomes included: rates of change in minimum joint space width (JSW) of the lateral compartment, and compartments of the contra-lateral knee, change in Kellgren-Lawrence grade, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Get-up and Go test.
Methods: RCT; Multicenter
Time: Patients were followed for 3 years.
What were the important findings?
What should I remember most?
How will this affect the care of my patients?
The authors responsible for this critical appraisal and ACE Report indicate no potential conflicts of interest relating to the content in the original publication.