Nilgun ÜSTÜN, Ayşe TURHANOĞLU. Vitamin D Levels in Patients With Ankylosing Spondylitis and Its Relationship With Disease Activity. Archives of Rheumatology [Internet]. 2014 Dec. 31 [cited 2025 Oct. 18];29(4):321-2. Available from: https://www.archivesofrheumatology.org/index.php/pub/article/view/698