Correlation Between Vitamin-D and Degenerative Joint Disorders. Review and Meta-analysis

Objectives: Evaluate the evidence of the clinical correlation between vitamin D and symptomatic degenerative joint disease.
Methods: A systematic search and meta-analysis was conducted of randomized controlled studies (RCTs) published in between January 1^st 2010 and March^th 2020 on five different databases. The study population consisted of adult patients with symptomatic knee osteoarthritis; the intervention: vitamin D; the comparison: placebo and the outcomes included the Western Ontario and McMaster Universities Arthritis Index (WOMAC) (pain, function, stiffness), tibial Cartilage volume, synovial tissue volume (STV), subchondral bone marrow lesion (BML) volume, effusion-synovitis, serum vitamin D3 levels, serological inflammatory and metabolic biomarkers levels and adverse events.
Results: Nine RCTs involving 2.168 patients were included in this study. Pooled estimates suggested that vitamin D supplementation was associated with significant reduction in WOMAC pain (Std. Mean=1.08(0.90, 1.25); I²=99%; p=0.00001), function (Std. Mean=1.1(0.92, 1.27); I²=99%; p=0.00001), stiffness (Std. Mean=0.72(0.54, 0.90); I²=98%; p=0.00001) and effusion-synovial in the suprapatellar pouch. There was no significant difference in incidence of tibial cartilage volume (Std. Mean=0.62(0.44,0.80); I²=99%; p=0.00001), STV, BML volume, inflammatory biomarkers and adverse events between the vitamin D and the placebo groups.

Conclusions: Vitamin D supplementation was effective in improving the WOMAC pain and function in patients with knee OA. However, it had no beneficial effect on structural change of the cartilage and in the reduction of inflammatory biomarkers. Therefore, there is currently a lack of evidence to support the use of vitamin D supplementation in preventing the progression of knee OA.