The instruments used in this childhood MR asthma study were only the CYP2R1 and GC SNPs and did not include the SNPs near DHCR7 and CYPR24A1. Our study thus provides a more thorough examination of the effects of 25OHD on asthma risk by using a substantially larger sample size, including all 25OHD-associated loci, in both adult and childhood asthma. Here, CYP2R1 is linked to asthma.