title: Con: Nutritional vitamin D replacement in chronic kidney disease and end-stage renal disease.
abstract: Insufficiency of 25-hydroxyvitamin D [25(OH)D] is highly prevalent among patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD) and is a critical component in the pathogenesis of secondary hyperparathyroidism. Accordingly, current National Kidney Foundation-Kidney Disease Outcomes Quality Initiative and Kidney Disease: Improving Global Outcomes guidelines recommend the correction of hypovitaminosis D through nutritional vitamin D replacement as a first-step therapeutic approach targeting secondary hyperparathyroidism. In this Polar Views debate, we summarize the existing evidence, aiming to defend the position that nutritional vitamin D replacement is not evidence-based and should not be applied to patients with CKD. This position is supported by the following: (i) our meta-analysis of randomized controlled trials shows that whereas nutritional vitamin D significantly increases serum 25(OH)D levels relative to placebo, there is no evidence either in predialysis CKD or in ESRD that parathyroid hormone (PTH) is lowered; (ii) on the other hand, in randomized head-to-head comparisons, nutritional vitamin D is shown to be inferior to activated vitamin D analogs in reducing PTH levels; (iii) nutritional vitamin D is reported to exert minimal to no beneficial actions in a series of surrogate risk factors, including aortic stiffness, left ventricular mass index (LVMI), epoetin utilization and immune function among others; and (iv) there is no evidence to support a benefit of nutritional vitamin D on survival and other 'hard' clinical outcomes. Whereas nutritional vitamin D replacement may restore 25(OH)D concentration to near normal, the real target of treating vitamin D insufficiency is to treat secondary hyperparathyroidism, which is untouched by nutritional vitamin D. Furthermore, the pleotropic benefits of nutritional vitamin D remain to be proven. Thus, there is little, if any, benefit of nutritional vitamin D replacement in CKD.
authors.affiliation: Department of Medicine, Indiana University School of Medicine and Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Agarwal
authors.affiliation: Division of Nephrology and Hypertension1st Department of Medicine, AHEPA Hospital, Aristotle University of Thessaloniki, Greece.
authors.forename: Panagiotis I
authors.initials: PI
authors.lastname: Georgianos
mesh_terms: D019587:Dietary Supplements; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000188:drug therapy* / Q000209:etiology; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D014807:Vitamin D
keywords: CKD; cholecalciferol; nutritional vitamin D; secondary hyperparathyroidism