Patients with knee osteoarthritis gain little clinical benefit from vitamin D supplementation, new research suggests.
Supplements of vitamin D, the “sunshine vitamin”, are commonly taken to reduce bone loss and cartilage degradation. According to The JAMA Network, observational studies suggest that vitamin D supplements are associated with benefits for knee osteoarthritis, but current evidence from clinical trials is contradictory.
In a new study conducted in Tasmania and Melbourne, Australia, Dr. Changhai Ding of the University of Tasmania and colleagues randomly assigned 413 patients with symptomatic knee osteoarthritis and low vitamin D levels to receive monthly treatment with oral vitamin D3 (50,000 IU) or an identical placebo for two years.
The randomized, double-blind, placebo-controlled clinical trial aimed to compare the effects of vitamin D supplementation vs placebo on knee pain and knee cartilage volume in this patient group.
Results from the 340 participants who completed the study showed that, compared with placebo, vitamin D supplementation did not result in significant differences in change in MRI-measured tibial cartilage volume or a measure of knee pain over two years.
There were also no significant differences in change of tibiofemoral cartilage defects or change in tibiofemoral bone marrow lesions.
Vitamin D levels did increase more in the vitamin D group than in the placebo group over the study period, but the authors concluded that the findings “suggest a lack of evidence to support vitamin D supplementation for slowing disease progression or structural change in knee osteoarthritis.”