**Abstract**

Vitamin D deficiency is highly prevalent in patients with renal disease. The abnormal vitamin D (VD) metabolism in chronic kidney disease (CKD) is a key factor for developing CKD-related mineral bone disease (CKD-MBD), which directly influences the survival of the CKD patients. The importance of VD is perhaps of greater value due to its pleiotropic effects that span beyond calcium-phosphorus metabolism (cancer protection, diabetes prevention, and renal protection). The aim of our chapter is to depict the clinical implications of VD deficiency in the setting of CKD, including VD pleiotropy in renal disease, and to propose the most adequate treatment suggested in the literature.

**Keywords:** vitamin D deficiency, chronic kidney disease, mineral bone disease, vitamin D pleiotropy, vitamin D supplementation
