Role of vitamin D receptor activators in peritoneal dialysis.

Chronic kidney disease (CKD), including patients on peritoneal dialysis (PD), is linked to an important increase in mortality risk. Within the new systemic term CKD-MBD, alterations in vitamin D metabolism are also included. Many adverse events have been associated with vitamin D deficiency or lack of vitamin D receptor (VDR) activation both in the general population and CKD patients, and these associations seem to be maintained in PD patients. Particularities of PD in vitamin D metabolism, calcium balance, low PTH levels and the high prevalence of adynamic bone disease are discussed. We also review the associations of clinical or survival benefits with vitamin D supplementation, VDR or selective VDR activation, although they are low-graded and most of them obtained from HD databases. Nevertheless, we think that the combined approach to secondary hyperparathyroidism seems also to be appropriate in PD patients, and vitamin D (native plus VDR or selective VDR activation) seem an important part of the required integral approach. The later may provide additional benefits but definitive prove is still lacking.