 Vitamin D is a hormone promoting bone health, which also has a wide range of cellular activities including the differentiation of hematopoietic cells and down-regulation of inflammatory cytokines. Vitamin D has anti-inflammatory and immune-regulating properties and the maintenance of adequate vitamin D status may play a role in managing inflammation and immunity. Vitamin D supplementation in patients with chronic inflammatory conditions like chronic kidney disease improves the values of circulating markers of inflammation and immunity. Recently, it has been highlighted that in certain conditions, like chronic kidney disease, the administration of vitamin D reduces serum hepcidin values and transfusion requirements. 