title: Effect of cholecalciferol supplementation on urine podocyte-associated messenger RNAs in patients with chronic kidney disease.
abstract: BACKGROUND
  Vitamin D reduces albuminuria in patients with chronic kidney disease (CKD) but its effects on glomerular podocytes are not entirely understood.
  
  
  OBJECTIVE
  To evaluate if cholecalciferol supplementation reduces the levels of podocyte-associated urine mRNAs in patients with CKD.
  
  
  METHODS
  A total of 27 patients with stages 2 to 4 CKD and suboptimal serum vitamin D [25(OH)D] levels were treated with cholecalciferol for 6 months. Serum 25(OH)D level, estimated glomerular filtration rate (eGFR), proteinuria, and urine mRNA of nephrin, podocin, podocalyxin, transient receptor potential cation channel 6, vascular endothelial growth factor A, and transforming growth factor beta were assessed before and after intervention.
  
  
  RESULTS
  eGFR declined at an average rate of -4.71 mL/min/1.73 m2 (p = 0.010 vs. baseline), being 28 ± 16 mL/min/1.73 m2 at six months. No changes in proteinuria or mineral and bone metabolism parameters were observed after cholecalciferol supplementation. Urinary podocyte-associated mRNAs did not change significantly after treatment. However, patients who achieved 25(OH)D level > 20 ng/mL at six months showed a trend of reduction of urinary nephrin and podocin mRNA levels; in patients with 25(OH)D that remained < 20 ng/mL there was a significant increase in urinary podocalyxin, and a trend of higher expression of urinary nephrin and podocin mRNA.
  
  
  CONCLUSIONS
  Six months of cholecalciferol supplementation had no effect on urine podocyte-associated mRNA profile of patients with advanced CKD. The protective effect of vitamin D or its analogues on the glomerular podocyte should be investigated in early stages of CKD with a longer treatment period.
authors.affiliation: Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: João Rodolfo Teló
authors.initials: JR
authors.lastname: Timm
authors.affiliation: Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Karohl
authors.affiliation: Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Mariane Dos
authors.initials: MD
authors.lastname: Santos
authors.affiliation: Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Maysa Lucena de
authors.initials: ML
authors.lastname: Souza
authors.affiliation: Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Zancan
authors.affiliation: Universidade Federal de Pelotas, Brazil.
authors.forename: Rafael de
authors.initials: Rd
authors.lastname: Almeida
authors.affiliation: Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Francisco Veríssimo
authors.initials: FV
authors.lastname: Veronese
mesh_terms: D002762:Cholecalciferol / Q000494:pharmacology*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000652:urine*; D008297:Male; D008875:Middle Aged; D050199:Podocytes / Q000187:drug effects* / Q000378:metabolism; D011446:Prospective Studies; D012333:RNA, Messenger / Q000096:biosynthesis / Q000652:urine*; D014815:Vitamins / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D014815:Vitamins; D002762:Cholecalciferol