title: Vitamin concentrations 5 years after gastric bypass.
abstract: OBJECTIVE
  Few studies have investigated the effects of bariatric surgery on vitamin status in the long term. We examined changes in vitamin status up to 5 years after Roux-en-Y gastric bypass surgery.
  
  
  METHODS
  Using a retrospectively maintained database of patients undergoing weight loss surgery, we identified all patients operated with Roux-en-Y gastric bypass at our tertiary care hospital during July 2004-May 2008. Data on vitamin concentrations and patient-reported intake of dietary supplements were collected up to July 2012. Linear mixed models were used to estimate changes in vitamin concentrations during follow-up, adjusting for age and sex. All patients were recommended daily oral multivitamin, calcium/vitamin D and iron supplements and 3-monthly intramuscular B-12 after surgery.
  
  
  RESULTS
  Out of the 443 patients operated with gastric bypass, we included 441 (99.5%) patients with one or more measurements of vitamin concentrations (75.1% women; mean age 41.5 years, mean body mass index 46.1 kg/m(2) at baseline). At 5 years after surgery, the patients' estimated mean vitamin concentrations were either significantly higher (vitamin B-6, folic acid, vitamin B-12, vitamin C and vitamin A) or not significantly different (thiamine, 25-hydroxyvitamin D and lipid-adjusted vitamin E) compared with before surgery. Use of multivitamin, calcium/vitamin D and vitamin B-12 supplements was reported by 1-9% of patients before surgery, 79-84% of patients at 1 year and 52-83% of patients 5 years after surgery.
  
  
  CONCLUSIONS
  In patients who underwent gastric bypass surgery, estimated vitamin concentrations were either significantly increased or unchanged up to 5 years after surgery.
authors.affiliation: Department of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Aaseth
authors.affiliation: Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway.
authors.forename: M W
authors.initials: MW
authors.lastname: Fagerland
authors.affiliation: Department of Nutrition and Dietetics, Oslo University Hospital, Oslo, Norway.
authors.forename: A-M
authors.initials: AM
authors.lastname: Aas
authors.affiliation: Department of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Hewitt
authors.affiliation: Department of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: H
authors.initials: H
authors.lastname: Risstad
authors.affiliation: Department of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Kristinsson
authors.affiliation: Department of Endocrinology, Oslo University Hospital, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Bøhmer
authors.affiliation: Department of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Mala
authors.affiliation: Department of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: E T
authors.initials: ET
authors.lastname: Aasheim
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000097:blood; D015992:Body Mass Index; D019587:Dietary Supplements; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D008297:Male; D009752:Nutritional Status; D009767:Obesity, Morbid / Q000097:blood / Q000601:surgery*; D012189:Retrospective Studies; D014801:Vitamin A / Q000097:blood; D014803:Vitamin B Complex / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014810:Vitamin E / Q000097:blood; D014815:Vitamins / Q000097:blood*; D015431:Weight Loss
chemical_list: D014815:Vitamins; D014801:Vitamin A; D014803:Vitamin B Complex; D014807:Vitamin D; D014810:Vitamin E; C104450:25-hydroxyvitamin D; D001205:Ascorbic Acid