Hypovitaminosis D in children with familial Mediterranean fever.

PURPOSE Vitamin D deficiency or insufficiency plays a role in the initiation and perpetuation of certain autoimmune diseases. The purpose of this study was to measure the vitamin D status of children with Familial Mediterranean Fever (FMF) and compare it to their healthy peers. METHODS A total of 50 FMF patients and 49 healthy children were enrolled in this prospective study. Vitamin D levels were measured via HPLC. Demographic data, FMF symptom severity scores and the levels of other disease activity markers were retrieved from our hospital database. RESULTS The mean age and gender balance of patients and controls were similar, being 8.4 ± 3.8 years and 19 male patients, and 9.1 ± 3.0 years and 25 male controls, respectively. The mean 25(-OH) vitamin D3 levels were 15.94 ± 9.66 µg/L in FMF patients and 41.22 ± 21.31 µg/L in controls. Vitamin D levels were normal in 12% of FMF patients, insufficient in 62% and deficient in 26%. No vitamin D deficiency was evident in any control subject; 30% had insufficient and 70% had normal vitamin D levels. Plasma vitamin D3 levels were similar in all patients despite varying FMF symptom severity scores. CONCLUSIONS Vitamin D deficiency is frequent in children with FMF but is not associated with disease severity score.