Association of Vitamin D Status with Radiographic Changes in Knee Osteoarthritis Patients

BACKGROUND: Knee osteoarthritis (KOA) is a common degenerative joint disease and a major cause of pain and disability among older adults. Vitamin D plays an important role in musculoskeletal function, yet its association with radiographic severity of KOA remains unclear, particularly in South Asian populations where deficiency is widespread. This study aimed to assess the relationship between serum vitamin D levels and radiographic KOA among patients attending a tertiary care center in Bangladesh. METHODS: A cross-sectional analytical study was conducted at the Department of Physical Medicine and Rehabilitation at Bangladesh Medical University (BMU), Dhaka, Bangladesh. Patients aged ≥50 years presenting with knee pain were screened, and 90 individuals fulfilling the American College of Rheumatology (ACR) criteria for primary KOA were enrolled through purposive sampling. Weight-bearing anteroposterior and lateral knee radiographs were obtained and graded using the Kellgren-Lawrence (K-L) classification. Serum 25-hydroxyvitamin D levels were measured using the Abbott Architect chemiluminescent microparticle immunoassay (CMIA) assay (Abbott Laboratories, Abbott Park, IL, USA). Vitamin D status was categorized as deficient (