CYP2R1 and vitamin D deficiency: Alleles of genes encoding proteins involved in vitamin D metabolism and functioning, such as GC, DHCR7, CYP2R1 and CYP24A1, have been associated with a risk of vitamin D insufficiency and may be further implicated in food sensitization (Table 1).63 Variations in the gene that encodes for vitamin D‐binding protein (VDBP), GC, could implicate the role of vitamin D in the immune system.