Serum inflammatory factors, vitamin D levels, and asthma severity in children with comorbid asthma and obesity/overweight: a comparative study - Jiang, Wan-yu; Jiao, Rong-hong; Ma, Su-li; Dai, Jin-sheng; Zhu, Hai-feng; Wu, Meng-ya; Che, Yan-ran; Zhang, Lei; Ding, Xiao-yuan (Frontiers in Pediatrics, 2025)