Vitamin D-binding protein (DBP)

Vitamin D-binding protein (DBP) is a multifunctional plasma glycoprotein encoded by the GC gene on chromosome 4. It is the principal carrier for all vitamin D metabolites in circulation, binding and transporting vitamin D2, D3, and their hydroxylated metabolites between organs such as skin, liver, kidney, and target tissues. DBP also scavenges extracellular actin released during cell injury, binds fatty acids, and can modulate immune responses, including macrophage activation and chemotaxis. Genetic variants of DBP significantly affect vitamin D status and have been associated with susceptibility to various diseases. Although essential for vitamin D metabolism and homeostasis, DBP itself is not a typical drug target, but is of clinical and biomarker interest in settings affecting vitamin D transport or status.

Other names

DBPGc-globulinGroup-specific componentGc protein-derived macrophage activating factor (Gc-MAF)GcMAFGcVitamin D-binding protein-macrophage activating factor

Not a direct therapeutic target but functions as a carrier: modulates the bioavailability of vitamin D metabolites by binding and transport. Gc-MAF (derived from DBP) has been investigated for activating macrophages as an experimental therapeutic approach, primarily for immunomodulation, but this is not a mainstream or approved mechanism.