Twenty-five-hydroxyvitamin D (25(OH)-vitamin D) is crucial in the regulation of immunologic processes, but-although its deficiency has been reported in patients with different rheumatological disorders-no data are available for Kawasaki disease (KD). The goals of this study were to assess the serum levels of 25(OH)-vitamin D in children with KD and evaluate the relationship with the eventual occurrence of KD-related vascular abnormalities. We evaluated serum 25(OH)-vitamin D levels in 79 children with KD (21 females, 58 males, median age 4.9 years, range 1.4-7.5 years) in comparison with healthy sex-/age-matched controls. A significantly higher percentage of KD patients (98.7 %) were shown to have reduced 25(OH)-vitamin D levels (<30 ng/mL) in comparison with controls (78.6 %, p < 0.0001). Furthermore, KD patients had severely low levels of 25(OH)-vitamin D than controls (9.17 ± 4.94 vs 23.3 ± 10.6 ng/mL, p < 0.0001), especially the subgroup who developed coronary artery abnormalities (4.92 ± 1.36 vs 9.41 ± 4.95 ng/mL, p < 0.0001). In addition, serum 25(OH)-vitamin D levels correlated not only with erythrosedimentation rate (p < 0.0001), C-reactive protein (p < 0.0001), hemoglobin level at KD diagnosis (p < 0.0001) but also with both coronary artery aneurysms (p = 0.005) and non-aneurysmatic cardiovascular lesions (p < 0.05). Low serum concentrations of 25(OH)-vitamin D might have a contributive role in the development of coronary artery complications observed in children with KD.
Keywords: 25(OH)-vitamin D; Coronary artery aneurysms; Kawasaki disease.