CYP27B1 and vitamin D deficiency: However, SNPs for CYP27B1 and GC-rs7041 were found to be significantly associated with vitamin-D deficiency where SNP for CYP27B1 (β = 1.61; 95% CI 2.79, 0.42; p-value < 0.05) was positively and GC-rs7041 (β =  − 1.33; 95% CI  − 0.02, − 2.64; p-value < 0.05) was negatively associated with it.