Decreased serum vitamin B12 and vitamin D levels affect sleep quality in children with familial Mediterranean fever.

Familial Mediterranean fever is an autoinflammatory disorder characterized by recurrent fever and serositis. We aimed to describe serum vitamin B12 and vitamin D levels and their correlation with self-reported sleep quality of pediatric FMF patients. Sixty-three children with FMF were enrolled to the study. Information on sleep quality was obtained using self-administration of Pittsburg Sleep Quality Index (PSQI). The patients were divided into subgroups depending on vitamin D serum concentrations: ≥ 20 and < 20 ng/ml. We also grouped patients according to their serum B12 concentration: ≥ 200, < 200 pg/ml. B12 levels were not correlated with PSQI scores, whereas significant correlation was found between vitamin D and total PSQI scores and daytime sleepiness. Total PSQI score, sleep disorders and daytime sleepiness sub-scores were statistically high in patients with serum D vitamin levels below 20 ng/ml. Sleep efficiency was found lower in patients with serum B12 levels below 200 pg/ml. B12 may have a positive role on effective sleep. More importantly, we suggest that vitamin D is protective against sleep disorders and poor sleep, it may also improve daytime activities.