title: Dietary vitamin K2 supplement improves bone status after lung and heart transplantation.
abstract: BACKGROUND
  Osteoporosis is a problem after transplantation. Studies since the last year indicate that vitamin K plays a role in optimal bone health. The aim of this randomized, double blind, prospective longitudinal study was to investigate the effect of a dietary supplement with vitamin K2 (180 microg menakinon-7) on bone mass, the first year after lung and heart transplantation.
  
  
  METHODS
  After preoperative baseline investigation of bone mass and bone-related biochemistry, 35 lung and 59 heart recipients were postoperatively randomized to vitamin K2 or placebo and reinvestigated the following year.
  
  
  RESULTS
  In all recipients, 1 year after solid organ transplantation, the difference between vitamin K2 and placebo for the lumbar spine (L2-L4) bone mineral density (BMD) was 0.028 (SE 0.014) g/cm(2), P=0.055 and for L2 to L4 bone mineral content was 1.33 (SE 1.91) g/cm(2) (P=0.5). In lung recipients separately, the difference for bone mineral content was 3.39 g (SE 1.65), P=0.048 and in heart recipients 0.45 (SE 0.02) g, P=0.9 after controlling for baseline measures. In a forward stepwise linear regression analysis fitted to model differences in the L2 to L4 BMD, controlled for possible confounding variables (including use of bisphosphonate), and the only significant predictors were organ (B=-0.065 g/cm(2), P<0.001) and vitamin K2 (B=0.034 g/cm(2), P=0.019). Insufficient vitamin D status was common, and the parathyroid hormone was highest in the K2 group indicating a higher need for vitamin D.
  
  
  CONCLUSIONS
  One year of vitamin K2 supplement suggest a favorable effect on lumbar spine BMD with different response in lung and heart recipients. Vitamin D status should receive more attention.
authors.affiliation: Medical Department, Rikshospitalet, Oslo University Hospital, Oslo, Norway. liv.forli@rikshospitalet.no
authors.forename: Liv
authors.initials: L
authors.lastname: Forli
authors.forename: Jens
authors.initials: J
authors.lastname: Bollerslev
authors.forename: Svein
authors.initials: S
authors.lastname: Simonsen
authors.forename: Gunhild A
authors.initials: GA
authors.lastname: Isaksen
authors.forename: Kari E
authors.initials: KE
authors.lastname: Kvamsdal
authors.forename: Kristin
authors.initials: K
authors.lastname: Godang
authors.forename: Gaut
authors.initials: G
authors.lastname: Gadeholt
authors.forename: Are H
authors.initials: AH
authors.lastname: Pripp
authors.forename: Oystein
authors.initials: O
authors.lastname: Bjortuft
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects / Q000503:physiopathology*; D004311:Double-Blind Method; D005260:Female; D016027:Heart Transplantation / Q000009:adverse effects* / Q000276:immunology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008137:Longitudinal Studies; D016040:Lung Transplantation / Q000009:adverse effects* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000517:prevention & control*; D010919:Placebos; D012044:Regression Analysis; D024482:Vitamin K 2 / Q000031:analogs & derivatives / Q000097:blood / Q000627:therapeutic use*; D014815:Vitamins
chemical_list: D007166:Immunosuppressive Agents; D010919:Placebos; D014815:Vitamins; D024482:Vitamin K 2; C062629:menaquinone 7