title: Calcium supplements lower bone resorption after renal transplant.
abstract: OBJECTIVE
  Bone loss in renal transplant (RT) patients is a problem that begins during end-stage kidney disease and persists after transplantation. Suppression of parathyroid hormone (PTH) may decrease bone loss and improve fracture rate.
  
  
  METHODS
  A single-group prospective intervention study involving 30 patients was performed at a large RT unit. Investigations included dual-emission X-ray absorptiometry scan, vertebral X-ray, calcium absorption test, 24-h urinary calcium and serum measurements of total and ionized calcium, PTH, C-telopeptide cross-links (CTX), osteocalcin, alkaline phosphatase, 25 hydroxyvitamin D (25[OH]D), and 1,25-dihydroxyvitamin D3. Patients were given 500 mg elemental calcium daily for seven d, and serum measurements were repeated.
  
  
  RESULTS
  Two-tailed Wilcoxon rank-sum test showed significant decreases in PTH (p<0.01) and CTX (p<0.01) after calcium load. Dietary calcium, mean calcium absorption, and urinary calcium excretion were below desirable levels. Mean 25 hydroxyvitamin D (25(OH)D) was low, but levels of 1,25-dihydroxyvitamin D3 were normal. Calcium absorption significantly correlated with change in PTH (p<0.001), baseline 25(OH)D (p<0.001), and mycophenolate dose (p=0.024).
  
  
  CONCLUSIONS
  Calcium malabsorption is prevalent in RT recipients, contributing to bone destruction and compounded by poor dietary intake and low 25(OH)D. Calcium supplementation appears to help overcome this deficiency and acutely suppress PTH. Calcium may be an effective and inexpensive therapy for bone loss in RT recipients.
authors.affiliation: Department of Nephrology and Transplantation Services, The Queen Elizabeth Hospital, Adelaide, SA, Australia.
authors.forename: Raymond W
authors.initials: RW
authors.lastname: Yu
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Faull
authors.forename: P Toby H
authors.initials: PT
authors.lastname: Coates
authors.forename: Penelope S
authors.initials: PS
authors.lastname: Coates
mesh_terms: D015502:Absorptiometry, Photon; D001862:Bone Resorption / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D002112:Calcifediol / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D019355:Calcium Citrate / Q000008:administration & dosage*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D019355:Calcium Citrate; D002112:Calcifediol; D002118:Calcium