Vitamin D Deficiency is Associated with Knee Osteoarthritis and is Implicated in the Osteoarthritis Severity

Background: Levels of Vitamin D may impact the development and progression of knee osteoarthritis (OA), a disorder common in elderly people The aim of this study was to investigate the association between serum Vitamin D deficiency and knee OA.

Methods: One hundred twenty (40 male and 80 female) consecutive patients were recruited from the rheumatology outpatient clinic for the study. X-rays in two anterior-posterior and lateral views of the knees were performed for all patients. Staging of knee OA was done according to Kellgren-Lawrence criteria and divided into two groups; group A consisting of grades 1 and 2, and group B, consisting of grades 3 and 4. One hundred (30 male and 70 female) healthy individuals without clinical and radiographic signs of the disease were defined as a control group. Hematological and biochemical investigations, including measurement of 25-hydroxyvitamin D serum level, were performed for all participants. Pain intensity using a visual analog scale (VAS) and disease severity using the Western Ontario and McMaster Universities Arthritis Index was measured for all patients.

Results: The mean age of patients and controls were 60±3.5 and 54±2.6 years, respectively. Vitamin D levels of patients and controls were 13±3.3 and 32±2.5, respectively. More severe disease and diseases with prolonged duration were associated with a lower vitamin D level, and low vitamin D levels were associated with high VAS and WOMAC.

Conclusion: Vitamin D deficiency was associated with the development and the severity of knee OA as well as with the disease duration.