title: Time-course changes in bone turnover markers and fat-soluble vitamins after obesity surgery.
abstract: BACKGROUND
  The available evidence indicates a progressive increase in the incidence and severity of the deficiency of certain vitamins and related clinical conditions (i.e., metabolic bone disease). Because of the potential role of fat-soluble vitamins and carotenoids in bone metabolism, our aim was to assess the time-course changes of fat-soluble vitamins and serum markers of bone metabolism in candidates for obesity surgery and following two bariatric procedures.
  
  
  METHODS
  Sixty-five candidates for bariatric surgery and 150 serum samples after obesity surgery (i.e., Roux-en-Y gastric bypass, n = 85; biliopancreatic diversion, n = 65) were consecutively analyzed over a period of more than 2 years. Retinol, α- and γ-tocopherol, 25-OH-vitamin D3, β-cryptoxanthin, and β-carotene were analyzed by high-performance liquid chromatography. Calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone (iPTH), osteocalcin, beta-crosslaps, and N-terminal peptide of procollagen I (P1NP) were determined using commercial kits.
  
  
  RESULTS
  Retinol, β-cryptoxanthin, β-carotene, and α- and γ-tocopherol levels were significantly lower in post-surgery samples while osteocalcin, b-crosslaps, and P1NP were significantly increased. Along the time and regardless of the surgical procedure, P1NP, b-crosslaps, and osteocalcin increased during the first 12-24 months but declined afterward. 25-OH-vitamin D increased during the first 12 months and tended to decrease afterward while iPTH remained constant or decreased but increased after 1 year in both groups. Vitamin A remained constant but α- and γ-tocopherol, β-cryptoxanthin, and β-carotene decreased in both groups.
  
  
  CONCLUSIONS
  In addition to the nutritional assessment, regular monitoring of bone markers seems necessary in these patients and the early introduction of preventive strategies (i.e., the use of antiresorptive agents) should be evaluated.
authors.affiliation: Unidad de Vitaminas, Hospital Universitario Puerta de Hierro-Majadahonda, 28222, Madrid, Spain. fgranado.hpth@salud.madrid.org
authors.forename: Fernando
authors.initials: F
authors.lastname: Granado-Lorencio
authors.forename: Alberto
authors.initials: A
authors.lastname: Simal-Antón
authors.forename: Javier
authors.initials: J
authors.lastname: Salazar-Mosteiro
authors.forename: Carmen
authors.initials: C
authors.lastname: Herrero-Barbudo
authors.forename: Encarnación
authors.initials: E
authors.lastname: Donoso-Navarro
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Blanco-Navarro
authors.forename: Belen
authors.initials: B
authors.lastname: Pérez-Sacristán
mesh_terms: D000328:Adult; D001361:Avitaminosis / Q000097:blood* / Q000209:etiology; D050110:Bariatric Surgery / Q000009:adverse effects*; D001851:Bone Diseases, Metabolic / Q000175:diagnosis* / Q000209:etiology; D016723:Bone Remodeling / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014815:Vitamins / Q000097:blood*
chemical_list: D014815:Vitamins