title: Nutritional vitamin D supplementation and health-related outcomes in hemodialysis patients: a protocol for a systematic review and meta-analysis.
abstract: BACKGROUND
  The prevalence of vitamin D deficiency in hemodialysis patients is high. While most hemodialysis patients are treated with activated vitamin D (1,25[OH]2D) to prevent renal osteodystrophy, clinical practices of the screening and treatment of 25(OH)2D deficiency are highly variable. It is unclear if nutritional vitamin D supplementation with D2 or D3 provides an additional clinical benefit beyond that provided by activated vitamin D treatment in this population.
  
  
  METHODS
  We will conduct a systematic review of nutritional vitamin D (D2/D3) supplementation and health-related outcomes in hemodialysis patients according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary objective is to assess the impact of nutritional vitamin D supplementation on clinical outcomes relevant in hemodialysis patients, such as mortality, cardiovascular events, infections, and fractures. Secondary outcomes will include anemia, hyperparathyroidism, medication use (erythrocyte-stimulating agents, activated vitamin D), and quality of life. We will search MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov for randomized, controlled trials of nutritional vitamin D supplementation (ergocalciferol/D2 or cholecalciferol/D3) in chronic hemodialysis patients. The Cochrane Risk Assessment Tool will be used to assess the quality of eligible studies. We will perform meta-analyses using standard techniques for the outcomes listed above if pooling is deemed appropriate/sufficient. The results of this systematic review may highlight gaps in our knowledge of the relevance of nutritional vitamin D in end-stage renal disease, allowing for the informed design of clinical trials assessing the impact of nutritional vitamin D therapy in the hemodialysis population in the future.
  
  
  BACKGROUND
  PROSPERO CRD42014013931.
authors: Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1243, New York, NY, 10029, USA. Anita.Mehrotra@mssm.edu.
authors: Anita
authors: A
authors: Mehrotra
authors: Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1243, New York, NY, 10029, USA. WaiYin.Leung@mountsinai.org.
authors: Wai-Yin
authors: WY
authors: Leung
authors: Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1243, New York, NY, 10029, USA. Tannia.Joson@mssm.edu.
authors: Tannia
authors: T
authors: Joson
mesh_terms: D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control; D002762:Cholecalciferol / Q000627:therapeutic use*; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000209:etiology / Q000517:prevention & control; D002985:Clinical Protocols; D019587:Dietary Supplements; D004872:Ergocalciferols / Q000627:therapeutic use*; D050723:Fractures, Bone / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D007239:Infections / Q000209:etiology; D006435:Renal Dialysis / Q000009:adverse effects*; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000401:mortality; D012107:Research Design; D000078202:Systematic Reviews as Topic; D014808:Vitamin D Deficiency / Q000188:drug therapy* / Q000209:etiology; D014815:Vitamins / Q000627:therapeutic use*; D015201:Meta-Analysis as Topic
chemical_list: D004872:Ergocalciferols; D014815:Vitamins; D002762:Cholecalciferol