Vitamin D is associated with various pathological conditions such as cardiovascular diseases and cancer. We investigated the relationship between vitamin D and Kawasaki disease (KD).

We performed a retrospective review of the medical records of patients with KD between February 2013 and March 2016 in Daegu Fatima Hospital. Study participants were grouped according to vitamin D serum concentration. Group 1 included patients with 25(OH)-vitamin D ≥20 ng/mL. Group 2 included patients with 25(OH)-vitamin D <20 ng/mL. We analyzed the clinical characteristics and laboratory data of the 2 groups.

Of the 91 patients, 52 were included in group 1, and 39 in group 2. Group 1 patients had significantly higher levels of calcium, phosphate, albumin and sodium than group 2 patients did. There were no differences in clinical characteristics, but the proportion of patients with polymorphic rash was significantly higher in group 2. Resistance to intravenous immunoglobulin was more frequent in group 2 ( P =0.023). No significant difference in the incidence of coronary artery complications was observed.

Low vitamin D levels are associated with resistance to intravenous immunoglobulin therapy in KD. Vitamin D deficiency might be a risk factor for immunoglobulin resistance in KD.