These findings appear to conflict with the reported links between genomic variation/polymorphisms in several vitamin D system genes (VDR, GC, CYP24A1, CYP2R1, and DHCR7/NADSYN1) and differences in the response to vitamin D compounds in studies involving CRC patients [68,69,70,71,72,73]. Here, GC is linked to colorectal carcinoma.