Clinical Trial of Vitamin D
“Vitamin D supplementation at a dose sufficient to elevate serum levels above 30 ng/mL does not appear to have any symptom- or structure-modifying benefits for knee osteoarthritis,” said Timothy E. McAlindon, MD, MPH, Tufts Medical Center, Boston, Massachusetts, speaking here on November 8 at a press briefing sponsored by the ACR and, later, in an oral presentation.
Participants who markedly increased their ingestion of vitamin D supplement reduced their based pain scores by about 2.14 points compared with a reduction of 1.20 points among patients who were taking placebo as assessed by the Western Ontario and McMaster Universities Osteoarthritis Index. That difference, however, did not achieve statistical significance (P >.05).
Similarly, differences in the Chair Stand Test, tibia and femur volume and thickness, and minimum joint space width did not achieve differences that were statistically significant, said Dr. McAlindon.
In the study, 146 participants were randomised to either vitamin D 2,000 mg/day or placebo for 2 years. The goal of supplementation was to increase vitamin D levels above 30 ng/mL, achieved through an average increase of 15 ng/mL in the group taking vitamin D, while the placebo patients increased vitamin D levels by 1.8 ng/mL (P <.0001). The participants in this study were mainly white women with an average age of just over 62 years. Their average body mass index was 30.7. At baseline, their average vitamin D level was 22.3 ng/mL. The researchers performed physical-function tests and x-rays on each participant at the beginning of the study and again at 12 months. They also computed the knee-cartilage volume and thickness, and the bone-marrow lesion volume from the magnetic resonance imaging studies taken at the baseline and at 12 months to determine whether any changes had occurred. Dr. McAlindon suggested that other ongoing clinical trials with vitamin D in arthritis patients might give further direction as to how scientists might pursue further studies with the agent. He noted that, when tested in rigourous clinical trials, antioxidants, vitamin C, vitamin D, beta-carotene, and other supplements have failed to produce the positive results seen in anecdotal and observational reports. He added that he was surprised by the results. "When you spend … years on a project you hope for a positive outcome," Dr. McAlindon commented. News Source: DG News - Ed Susman
