Figure Legend
Figure 1: The metabolic pathway of vitamin D synthesis and the tissue
specific cellular response it mediates that may reduce COVID-19
severity. CYP2R1, CYP27A1, and CYP27B1 are the cytochrome enzymes
involve in the hydroxylation processes of cholecalciferol to the active
form of vitamin D, 1,25(OH)2D.
1,25(OH)2D then binds to VDR which forms a heterodimer
with retinoid X receptor (RXR). Interaction of the heterodimer with the
vitamin D response element (VDRE) leads to downstream target gene
regulation.