Association between colchicine resistance and vitamin D in familial Mediterranean fever.

Although colchicines are the only effective treatment of familial Mediterranean fever (FMF), resistance to colchicines (CR) which is observed in up to 30% of the patients is still a problem. Clinically, resistance to colchicine is defined as three or more attacks within the last 6 months period while using ≥2 mg/day colchicine. Previous studies have shown decreased vitamin D levels in FMF patients compared with healthy controls.