The effect of vitamin D supplementation on attacks in PFAPA syndrome patients with low vitamin D levels.

BACKGROUND-AIM: To evaluate the effect of vitamin D supplementation on the frequency and duration of attacks in patients of PFAPA syndrome with low vitamin D levels. METHODS: This retrospective study comprised PFAPA patients with vitamin D deficiency/insufficiency between 2018 and 2023. The frequency and duration of PFAPA attacks before and after vitamin D supplementation were noted. RESULTS: Seventy-one patients were included. Of the 71 patients, 24 (33.8%) had vitamin D insufficiency, and 47 (66.2%) had vitamin D deficiency. In patients with vitamin D insufficiency, mean attack frequency and mean attack duration before vitamin D supplementation were 4.3 +/- 1.9/year and 2.2 +/- 1.6 days, respectively, while mean attack frequency and mean attack duration after vitamin D supplementation were 3.5 +/- 2.7/year per year and 1.3 +/- 0.9 days respectively (p = 0.2, p = 0.2, respectively). In patients with vitamin D deficiency, mean attack frequency and mean attack duration before vitamin D supplementation were 7.4 +/- 2.1/year and 2.2 +/- 1.6 days, respectively, while mean attack frequency and mean attack duration after vitamin D supplementation were 3.3 +/- 2.4/year and 1.3 +/- 0.9 days respectively (p < 0.01, p = 0.04, respectively). When the vitamin D level and the frequency of attacks were compared, the cut-off value of vitamin D was found to be 29.7 nmol/L. CONCLUSIONS: In PFAPA patients with low vitamin D levels, the frequency and duration of PFAPA attacks were reduced with vitamin D supplementation. Especially at vitamin D level cut-off > 29.7 nmol/L, the frequency of attacks reduced significantly.