title: Comparison of two different vitamin D supplementation regimens with oral calcifediol in kidney transplant patients.
abstract: BACKGROUND
  Vitamin D deficiency is prevalent in kidney transplant recipients (KTR) and recommendations on how to replenish vitamin D deposits are scarce.
  
  
  OBJECTIVE
  To evaluate, in KTR, the safety and efficacy of calcifediol in two different vitamin D supplementation regimens, in order to assess the most suitable dose.
  
  
  METHODS
  Prospective observational study with two calcifediol supplementation regimens randomly prescribed by clinicians in liquid form, at 266 mcg doses, monthly or biweekly. We analyzed 168 KTR with a functioning allograft for more than 6 months. Patients receiving other vitamin D forms, calcimimetics or bisphosphonates were excluded. Before calcifediol initiation (pre-treatment levels) and after at least 3 months of treatment (post-treatment levels), we measured serum levels of 25-OH vitamin D (25(OH)D), parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium (sCa), phosphate (sPO4) and creatinine (sCreat).
  
  
  RESULTS
  In the monthly group (n = 72), 25(OH)D levels increased from 14 ng/ml [interquartile range, IQR 9-22] at baseline to 31 [20-38] (p = 0.000), PTH decreased from 124 pg/ml [87-172] to 114 [78-163] (p = 0.006), while sCa and sPO4 remained stable. In the biweekly group (n = 96), 25(OH)D increased from 14 ng/ml [9-20] at baseline to 39 [28-52] (p = 0), PTH decreased from 141 pg/ml [95-221] to 112 [90-180] (p = 0.000), sCa remained stable and sPO4 increased from 3.3 ± 0.6 mg/dl to 3.5 ± 0.6 (p = 0.003). Renal function remained stable in both groups.
  
  
  CONCLUSIONS
  Vitamin D reposition with oral calcifediol, in a biweekly or monthly regimen, is safe and effective in improving 25(OH)D blood levels and in decreasing PTH in kidney transplant recipients.
authors.affiliation: Nephrology and Kidney Transplant Department, Hospital Clinic, Villarroel, 170, 08036, Barcelona, Spain.
authors.forename: Xoana
authors.initials: X
authors.lastname: Barros
authors.affiliation: Nephrology and Kidney Transplant Department, Hospital Clinic, Villarroel, 170, 08036, Barcelona, Spain.
authors.forename: Nestor Y
authors.initials: NY
authors.lastname: Rodríguez
authors.affiliation: Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Fuster
authors.affiliation: Nephrology and Kidney Transplant Department, Hospital Clinic, Villarroel, 170, 08036, Barcelona, Spain.
authors.forename: Lida
authors.initials: L
authors.lastname: Rodas
authors.affiliation: Nephrology and Kidney Transplant Department, Hospital Clinic, Villarroel, 170, 08036, Barcelona, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Esforzado
authors.affiliation: Internal Medicine Department, Santa Maria della Misericordia Hospital, Rovigo, Italy. mazza.alberto@azisanrovigo.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Mazza
authors.affiliation: Nuclear Medicine Department, Santa Maria della Misericordia Hospital, Rovigo, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubello
authors.affiliation: Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Campos
authors.affiliation: Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Tapias
authors.affiliation: Nephrology and Kidney Transplant Department, Hospital Clinic, Villarroel, 170, 08036, Barcelona, Spain.
authors.forename: José-Vicente
authors.initials: JV
authors.lastname: Torregrosa
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002112:Calcifediol / Q000008:administration & dosage* / Q000009:adverse effects; D019587:Dietary Supplements / Q000009:adverse effects; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D011446:Prospective Studies; D013997:Time Factors; D066027:Transplant Recipients; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D014815:Vitamins / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D015415:Biomarkers; C470125:PTH protein, human; D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002112:Calcifediol
keywords: Calcifediol; Kidney transplant; Parathyroid hormone; Vitamin D