title: Serum 25(OH) vitamin D concentration changes after Roux-en-Y gastric bypass surgery.
abstract: OBJECTIVE
  To describe serum 25(OH)D changes after Roux-en-Y gastric bypass (RYGB) and to determine if fat mass (FM) loss and vitamin D intake are associated with changes in serum levels.
  
  
  METHODS
  The relationship between serum 25(OH)D and 1) FM, 2) weight, 3) % excess weight loss (EWL), and 4) BMI was investigated after controlling for potential confounders using a mixed effects linear model in 20 women before and up to 1-year post-RYGB. Subcutaneous (SAT) and visceral adipose tissue (VAT) vitamin D concentrations at time of RYGB were also evaluated.
  
  
  RESULTS
  Weight and FM decreased 1-year after surgery by 45 ± 1 kg and 37 ± 1 kg, respectively while 25(OH)D increased by 10 ± 2 ng mL(-1) . Weight, FM, BMI, and %EWL changes were associated with 25(OH)D change. VAT had an average 21% more vitamin D per gram than SAT and concentrations were highly correlated.
  
  
  CONCLUSIONS
  Although weight loss may lead to increased serum 25(OH)D after RYGB, low levels remain a concern in some patients 1-year postsurgery. Additional research is needed to clarify the relationship between adipose storage of vitamin D and serum 25(OH)D in obesity, and how that relationship might change after surgery. This could lead to improved clinical management of vitamin D in this ever-growing clinical population.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, Saint Paul, Minnesota, USA.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Beckman
authors.forename: Carrie P
authors.initials: CP
authors.lastname: Earthman
authors.forename: William
authors.initials: W
authors.lastname: Thomas
authors.forename: Charlene W
authors.initials: CW
authors.lastname: Compher
authors.forename: Juan
authors.initials: J
authors.lastname: Muniz
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Horst
authors.forename: Sayeed
authors.initials: S
authors.lastname: Ikramuddin
authors.forename: Todd A
authors.initials: TA
authors.lastname: Kellogg
authors.forename: Shalamar D
authors.initials: SD
authors.lastname: Sibley
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000713:Anastomosis, Roux-en-Y; D015992:Body Mass Index; D001835:Body Weight; D019587:Dietary Supplements; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D015596:Nutrition Assessment; D009765:Obesity / Q000097:blood / Q000601:surgery; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood; D015431:Weight Loss
chemical_list: D014807:Vitamin D