title: Vitamin D and Clinical Outcomes in Dialysis.
abstract: Most dialysis patients are vitamin D deficient, including deficiencies in both activated vitamin D (1, 25-dihydroxyvitamin D) and the less active 25-hydroxyvitamin D. These and other abnormalities associated with chronic kidney disease (CKD), if they remain untreated, lead to secondary hyperparathyroidism and bone changes, such as osteitis fibrosa cystica. Activated vitamin D has been proven to decrease parathyroid hormone (PTH) levels in dialysis patients and is currently used for this indication. There are multiple other potential "pleotrophic" effects associated with vitamin D therapy. These include associations with lower all-cause and cardiovascular mortality, lower rates of infections and improved glycemic indexes. Meta-analyses of multiple observational studies have shown activated vitamin D therapy to be associated with improved survival. Observational data also suggest fewer infections and better glucose control. There have been no randomized clinical trials powered to evaluate mortality or other clinical outcomes. Small trials of nutritional vitamin D (ergocalciferol and cholecalciferol) showed increases in 25-hydroxyvitamin D levels without hypercalcemia or hyperphosphatemia, even when given in addition to activated vitamin D therapy. While activated vitamin D therapy is associated with improved outcomes, it also leads to higher fibroblast growth factor 23 (FGF-23) levels, which may be detrimental in dialysis patients. Further research is needed to evaluate whether activated or nutritional vitamin D therapy are beneficial in dialysis patients for outcomes other than secondary hyperparathyroidism.
authors.affiliation: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York.
authors.forename: Coral
authors.initials: C
authors.lastname: Parikh
authors.affiliation: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York.
authors.forename: Victoria
authors.initials: V
authors.lastname: Gutgarts
authors.affiliation: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York.
authors.forename: Elliot
authors.initials: E
authors.lastname: Eisenberg
authors.affiliation: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York.
authors.forename: Michal L
authors.initials: ML
authors.lastname: Melamed
mesh_terms: D000089703:Fibroblast Growth Factor-23; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000150:complications / Q000188:drug therapy*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy*; D010281:Parathyroid Hormone / Q000097:blood; D006435:Renal Dialysis / Q000009:adverse effects*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000209:etiology / Q000517:prevention & control*
chemical_list: C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D014807:Vitamin D; D000089703:Fibroblast Growth Factor-23; C104450:25-hydroxyvitamin D