CYP19A1 and ankylosing spondylitis: Previous research has found significantly lower FD values in individuals using intravenous corticosteroids [16], aromatase inhibitors [27], antiepileptic drugs [28,29,30], selective serotonin reuptake inhibitors (SSRIs) [31], and in those diagnosed with conditions such as sickle cell anemia [32,33], osteoporosis [34], chronic renal failure [35], thalassemia major [36], psoriasis vulgaris [37], ankylosing spondylitis [38], hyperparathyroidism [39], and vitamin D deficiency [40] compared to control groups.