Vitamin D Receptor ApaI a Allele Is Associated with Better Childhood Asthma Control and Improvement in Ability for Daily Activities

Vitamin D levels have been suggested as a marker of disease severity in asthmatic children. Our aim was to investigate possible associations between the vitamin D receptor (VDR) FokI, BsmI , ApaI, and TaqI polymorphisms and asthma susceptibility and control in children. 127 Greek children with asthma and 91 healthy controls were genotyped for VDR FokI , BsmI ApaI, and TaqI polymorphisms using Sequenom MassARRAY iPLEX platform. Asthma control was assessed according to the Global Initiative for Asthma guidelines (GINA) and Childhood Asthma Control Test (C-ACT) and, for the first time, tested for its possible association with VDR SNPs. Asthmatic children were grouped as “controlled ( n =49)”, “partially controlled ( n =38),” and “uncontrolled ( n =40),” according to GINA classification. No association was found between VDR polymorphisms and asthma prevalence. Asthmatic children with the VDR ApaI aa genotype had significantly higher C-ACT score compared with asthmatic children carrying the AA/AC VDR ApaI genotypes ( p =0.011). The frequency of VDR ApaI aa genotype was significantly higher in controlled asthma group ( n =92) than uncontrolled asthma group ( n =35), according to C-ACT (24.5% vs 0.0%, p