title: Zinc absorption and zinc status are reduced after Roux-en-Y gastric bypass: a randomized study using 2 supplements.
abstract: BACKGROUND
  Micronutrient deficiencies are common in patients undergoing gastric bypass. The effect of this type of surgery on zinc absorption and zinc status is not well known.
  
  
  OBJECTIVE
  The objective was to evaluate the effects of Roux-en-Y gastric bypass (RYGBP) on zinc status and zinc absorption at different stages after surgery. We hypothesized that zinc status would be significantly impaired after surgery and that this impairment would be less severe in subjects receiving increased supplemental zinc. We also hypothesized that zinc absorption would be lower after surgery.
  
  
  METHODS
  Anthropometric and body-composition variables and dietary and biochemical indexes of zinc status and zinc absorption were determined in 67 severe and morbidly obese women [mean (±SD) age: 36.9 ± 9.8 y; BMI (in kg/m(2)): 45.2 ± 4.7] who underwent RYGBP. The subjects were randomly assigned to 1 of 2 vitamin-mineral supplementation groups. Measurements were made before and 6, 12, and 18 mo after surgery. Fifty-six subjects completed the 18-mo follow-up.
  
  
  RESULTS
  Mean plasma zinc, erythrocyte membrane alkaline phosphatase activity, and the size of the rapidly exchangeable zinc pool decreased after RYGBP. Percentage zinc absorption decreased significantly from 32.3% to 13.6% at 6 mo after RYGBP and to 21% at 18 mo after surgery. No effect of supplement type was observed.
  
  
  CONCLUSIONS
  Zinc status is impaired after RYGBP, despite the finding that dietary plus supplemental zinc doubled recommended zinc intakes in healthy persons. Zinc absorption capacity is significantly reduced soon after RYGBP, with no major changes until 18 mo after surgery.
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile. mruz@med.uchile.cl
authors.forename: Manuel
authors.initials: M
authors.lastname: Ruz
authors.forename: Fernando
authors.initials: F
authors.lastname: Carrasco
authors.forename: Pamela
authors.initials: P
authors.lastname: Rojas
authors.forename: Juana
authors.initials: J
authors.lastname: Codoceo
authors.forename: Jorge
authors.initials: J
authors.lastname: Inostroza
authors.forename: Karen
authors.initials: K
authors.lastname: Basfi-fer
authors.forename: Attila
authors.initials: A
authors.lastname: Csendes
authors.forename: Karin
authors.initials: K
authors.lastname: Papapietro
authors.forename: Fernando
authors.initials: F
authors.lastname: Pizarro
authors.forename: Manuel
authors.initials: M
authors.lastname: Olivares
authors.forename: Lei
authors.initials: L
authors.lastname: Sian
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Westcott
authors.forename: Leland V
authors.initials: LV
authors.lastname: Miller
authors.forename: K Michael
authors.initials: KM
authors.lastname: Hambidge
authors.forename: Nancy F
authors.initials: NF
authors.lastname: Krebs
mesh_terms: D000293:Adolescent; D000328:Adult; D000469:Alkaline Phosphatase / Q000378:metabolism; D000886:Anthropometry; D001823:Body Composition; D015992:Body Mass Index; D003677:Deficiency Diseases / Q000097:blood / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D019587:Dietary Supplements / Q000009:adverse effects; D004910:Erythrocyte Membrane / Q000201:enzymology; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D006197:Hair / Q000737:chemistry; D006801:Humans; D007408:Intestinal Absorption; D008875:Middle Aged; D009752:Nutritional Status; D009765:Obesity / Q000601:surgery; D009767:Obesity, Morbid / Q000601:surgery; D010352:Patient Dropouts; D016037:Single-Blind Method; D013997:Time Factors; D055815:Young Adult; D015032:Zinc / Q000097:blood / Q000172:deficiency / Q000378:metabolism* / Q000627:therapeutic use*
chemical_list: D000469:Alkaline Phosphatase; D015032:Zinc