[Control of phosphorus and treatment with vitamin D in chronic kidney disease prior to the start of dialysis]

Hyperphosphatemia is a complication that appears in the early stages of chronic kidney disease (CKD) and that has been shown to have serious consequences in kidney disease patients. New phosphate regulators are currently being studied such as FGF- 23, a counter-regulatory phosphaturic hormone for vitamin D, and klotho, a cofactor necessary for activation of FGF-23. The main consequences of hyperphosphatemia described in CKD patients not on dialysis are ectopic calcification, increased mortality and more rapid progression of CKD. All this indicates the need for strict control of Pi. The two most currently used drugs for this purpose are lanthanum carbonate and sevelamer. Although there are no studies specifically designed for this predialysis population, these drugs appear to be effective and safe. Another complication of CKD is vitamin D deficiency which, according to recently published studies, is more prevalent and appears in earlier stages of the disease than was initially thought. There is wide debate on the need to administer vitamin D supplements systematically due to the pleiotropic effects of this hormone and which are unrelated to development of renal bone disease. Because of these doubts, there is no agreement on routine administration, although there is consensus on the need to measure 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D values and to wait for the result of numerous studies that are being carried out on the impact of vitamin D on progression of cardiovascular risk factors in CKD and the possible consequences of its indiscriminate administration.