title: Vitamin D treatment and mortality in chronic kidney disease: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Hypovitaminosis D has been associated with an increased cardiovascular mortality in the general population and in patients with chronic kidney disease (CKD). Still, whether prescribing vitamin D reduces the risk of mortality in renal patients remains controversial.
  
  
  METHODS
  We searched PubMed, ClinicalTrials.gov and the Cochrane Library for long-term longitudinal studies comparing vitamin D compounds (25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and synthetic derivatives) to placebo or no treatment in renal patients, and which evaluated mortality, to perform a meta-analysis. Data concerning study quality, population and effect size were extracted independently by two investigators using predefined forms.
  
  
  RESULTS
  Fourteen observational studies (194,932 patients) met all eligibility criteria. Most studies were performed in hemodialysis patients and all used calcitriol or synthetic analogues. In a random effects meta-analysis, receiving any vitamin D therapy significantly reduced the risk of all-cause mortality (relative risk 0.73, 95% CI 0.65-0.82). The relative risk of death was 0.72 (95% CI 0.65-0.80) after 3 years of therapy and 0.67 (95% CI 0.45-0.98) after 5 years. In meta-regression, the risk reduction was shown to be greater in patients with higher parathyroid hormone serum levels (p = 0.01). The risk of cardiovascular mortality was also significantly reduced in patients receiving any vitamin D derivative (relative risk 0.63, 95% CI 0.44-0.92).
  
  
  CONCLUSIONS
  Therapies with 1,25-dihydroxyvitamin D and analogues are associated with reduced mortality in CKD patients, and particularly in those suffering from secondary hyperparathyroidism. These results, based on observational evidence, are supportive of prescribing vitamin D therapies to CKD patients, while respecting good practice guidelines.
authors: RD-Néphrologie, Institut Universitaire de Recherche Clinique, Montpellier, France.
authors: Flore
authors: F
authors: Duranton
authors: Maria E
authors: ME
authors: Rodriguez-Ortiz
authors: Yohan
authors: Y
authors: Duny
authors: Mariano
authors: M
authors: Rodriguez
authors: Jean-Pierre
authors: JP
authors: Daurès
authors: Angel
authors: A
authors: Argilés
mesh_terms: D002117:Calcitriol / Q000031:analogs & derivatives / Q000627:therapeutic use*; D006962:Hyperparathyroidism, Secondary / Q000188:drug therapy / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000150:complications / Q000188:drug therapy / Q000401:mortality; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000188:drug therapy* / Q000401:mortality; D016896:Treatment Outcome; D014808:Vitamin D Deficiency / Q000150:complications / Q000188:drug therapy*; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D002117:Calcitriol