B. Fatih Kocyigit, A. Akyol, and T. Tulay Koca, “The relationship between vitamin D level and disease activity and focal erosion in rheumatoid arthritis ”, Ann Med Res , vol. 26, no. 1, pp. 0037–0041, May 2021, Accessed: Sep. 17, 2026. [Online]. Available: http://www.annalsmedres.org/index.php/aomr/article/view/1412