title: Effectiveness of B vitamin supplementation following bariatric surgery: rapid increases of serum vitamin B12.
abstract: BACKGROUND
  Few prospective studies have compared changes of nutrient intake while assessing effectiveness of thiamin, vitamin B12, and folate supplementation to prevent B vitamin deficiencies immediately following Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). Therefore, we determined the response to 3 months supplementation on maintaining blood B vitamin concentrations.
  
  
  METHODS
  Women undergoing RYGB (n = 11) and SG (n = 11) consumed bariatric vitamin supplements (12 mg thiamin, 350 μg vitamin B12, 800 μg folic acid) daily for 3 months. Height, weight, body mass index, and blood vitamin concentrations were measured preoperatively and at 3 months. Wilcoxon signed-rank analyses compared body weight parameters, laboratory indices, and nutrient intake at baseline and 3 months.
  
  
  RESULTS
  Supplementation for 3 months maintained blood thiamin, increased serum folate from 13.1 ± 5.4 to 16.3 ± 6.0 nmol/L (P = 0.049), and increased serum vitamin B12 concentrations from 498 ± 150 to 736 ± 340 pg/mL (P = 0.005). Dietary intake of thiamin and folate decreased in the combined surgical groups, while dietary intake of B12 was maintained. Bariatric B vitamin supplements provided multiple intakes of the Recommended Dietary Allowances (1090% thiamin, 14,583% vitamin B12, 200% folate).
  
  
  CONCLUSIONS
  Although energy intake decreased 64%, B vitamin supplementation for 3 months resulted in a 48% increase of serum vitamin B12, a modest increase of serum folate, and no reduction of blood thiamin concentrations. Long-term effects of the rapid rise of serum B12 levels attributed to the high content of supplements warrant further investigation.
authors.affiliation: Department of Nutrition and Foods Sciences, Texas Woman's University, 6700 Fannin, Houston, TX, 77030, USA, cmoore8@twu.edu.
authors.forename: Carolyn E
authors.initials: CE
authors.lastname: Moore
authors.forename: Vadim
authors.initials: V
authors.lastname: Sherman
mesh_terms: D000328:Adult; D050110:Bariatric Surgery / Q000009:adverse effects / Q000379:methods; D015992:Body Mass Index; D003131:Combined Modality Therapy; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000097:blood; D006801:Humans; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000188:drug therapy* / Q000601:surgery*; D011184:Postoperative Period; D011446:Prospective Studies; D016896:Treatment Outcome; D014805:Vitamin B 12 / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000517:prevention & control; D014803:Vitamin B Complex / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D014803:Vitamin B Complex; D005492:Folic Acid; D014805:Vitamin B 12