title: Prospective study of individualized or high fixed doses of vitamin D supplementation after bariatric surgery.
abstract: BACKGROUND
  The degree of bariatric surgery (BS) induced vitamin D (VD) malabsorption is not well established.
  
  
  OBJECTIVE
  The aim of this study is to evaluate the efficacy and safety of achieving 25-hydroxy VD (25(OH)D) levels ≥75 nmol/L with two regimens of VD supplementation after BS.
  
  
  METHODS
  We performed two open-label, prospective studies in patients undergoing BS from 2009 to 2011. Postoperatively, all patients received Ca citrate 1,000 mg and 800 IU of VD3/day. In the first study, additional VD3 was prescribed according to preoperative 25(OH)D levels- < 25 nmol/L:2,800 IU/day; 26-50 nmol/L:2,000-1,200 IU/day, 51-62 nmol/L:1,000 IU; >63 nmol/L:0 IU/day-and we evaluated the patients at baseline and at 4 months. In the second study, an additional fixed high dose of 2,000 IU/day of VD3 was administered, and we evaluated patients at baseline and at 4 and 12 months after BS.
  
  
  RESULTS
  The first study included 176 patients [mean age 44 (11)]; 140 were females. Before BS, 171 subjects (98 %) presented 25(OH)D levels <75 nmol/L. Postoperatively, the mean 25(OH)D levels increased from 40 (17) to 77 nmol/L (29) (p < 0.001) with no differences in parathormone (PTH) or 25(OH)D levels between dose groups. In the second study, we enrolled 52 patients [mean age 45 (10)]; 32 were females. Postoperatively, the mean 25(OH)D levels increased from 32 (12) to 80 (22) and to 75 nmol/L (15) (p < 0.001) at 4 and 12 months, respectively. In both studies, a high percentage of patients achieved 25(OH)D ≥75 nmol/L levels and no subject reported any serious adverse event.
  
  
  CONCLUSIONS
  Both schedules of daily VD3 supplementation were effective and safe under conditions of clinical practice.
authors.affiliation: Endocrinology and Nutrition Department, Obesity Unit, Hospital Clínic i Universitari, Villarroel, 170, Escalera 11, 2° piso, CP 08036, Barcelona, Spain, lflores@clinic.ub.es.
authors.forename: Lilliam
authors.initials: L
authors.lastname: Flores
authors.forename: Violeta
authors.initials: V
authors.lastname: Moizé
authors.forename: Emilio
authors.initials: E
authors.lastname: Ortega
authors.forename: Lucía
authors.initials: L
authors.lastname: Rodríguez
authors.forename: Alba
authors.initials: A
authors.lastname: Andreu
authors.forename: Xavier
authors.initials: X
authors.lastname: Filella
authors.forename: Josep
authors.initials: J
authors.lastname: Vidal
mesh_terms: D000328:Adult; D000368:Aged; D050110:Bariatric Surgery / Q000009:adverse effects; D019587:Dietary Supplements; D054796:Drug Dosage Calculations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000188:drug therapy* / Q000601:surgery*; D010281:Parathyroid Hormone / Q000097:blood; D011183:Postoperative Complications / Q000097:blood / Q000517:prevention & control; D057285:Precision Medicine / Q000379:methods*; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000517:prevention & control*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D
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