A large, multicenter trial compared the effects of taking a vitamin D supplement with a placebo on knee pain and knee cartilage volume in patients with symptomatic knee osteoarthritis who had low vitamin D levels. Patients were randomly assigned to take a monthly vitamin D3 supplement of 50,000 IU or a placebo pill for two years.
Researchers measured changes in tibial cartilage volume with magnetic resonance imaging (MRI) and collected pain score data. They also looked at cartilage defects and bone marrow lesions on MRI.
While the blood levels of vitamin D increased more in the vitamin D group compared with the placebo group, there were no significant differences in the rate of loss of tibial cartilage volume and reported pain scores. There were also no significant differences in changes in cartilage defects or bone marrow lesions between the two groups.
Vitamin D is important for bone health, but it will not decrease your pain or lessen cartilage loss.
Jane Langille is an award-winning health and medical writer based in the Toronto area. She writes on a broad range of health topics, including arthritis, cancer, heart health, food, fitness, precision medicine, and clinical trials. Find her on Twitter: @janelangille.