The Vitamin D Axis in Chronic Kidney Disease – State of the Art and Future Perspectives

Abstract All the components of the vitamin D axis participate in the pathogenesis of chronic kidney disease (CKD) and this knowledge can be exploited to devise targeted therapeutic strategies. The vitamin D axis includes vitamin D, vitamin D receptor and vitamin D-binding protein (VDBP), which is the precursor of a potent macrophage activating factor, group-specific component (Gc)-protein-derived macrophage activating factor (GcMAF), a protein that is being extensively studied after it was demonstrated that it eradicates advanced cancer and human immunodeficiency virus (HIV) infection. Thanks to its effects on the immune system and angiogenesis, it also appears to be a promising candidate for targeted therapy of CKD. In this article we shall summarise the state of the art on vitamin D and CKD, and then we shall focus on the perspectives opened by increasing knowledge of other components of the axis, in particular VDBP and GcMAF.