A mendelian randomization study conducted in China [42] investigated the effect of genetically lowered vitamin D levels on MetS and its related traits using a GRS constructed from four SNPs commonly associated with vitamin D, including rs12785878 in DHCR7, rs10741657 in CYP2R1, rs2282679 in GC and rs6013897 in CYP24A1. The gene discussed is DHCR7; the disease is metabolic syndrome.