Vitamin D and Its Effects on Articular Cartilage and Osteoarthritis

BACKGROUND: Osteoarthritis (OA) currently affects 10% of the American population. There has been a recent push to determine exactly what causes OA and how it can be treated most effectively. Serum vitamin D levels have been associated with OA and may have an effect on articular cartilage remodeling. PURPOSE: To critically review the published research on the effect of vitamin D on articular cartilage and the development of OA as well as on the mechanism behind cartilage regeneration and degeneration. STUDY DESIGN: Review. METHODS: A systematic search of PubMed and the Web of Science was performed for relevant studies published in the English language through April 30, 2016, using the terms vitamin D, articular cartilage, and osteoarthritis. RESULTS: On a molecular level, 1α,25(OH)(2)D(3), the activated form of vitamin D, plays a role in articular cartilage degeneration. Vitamin D binds to vitamin D receptors, triggering a signaling cascade that leads to chondrocyte hypertrophy. In clinical trials, vitamin D deficiency poses a risk factor for OA, and those with decreased cartilage thickness are more likely to be vitamin D–insufficient. CONCLUSION: The role of vitamin D supplementation in the treatment or prevention of OA remains uncertain. More research is needed to reconcile these conflicting findings.