title: Comparison Between Different Intramuscular Vitamin B12Supplementation Regimes: a Retrospective Matched Cohort Study.
abstract: The incidence of vitamin B12deficiency after bariatric surgery can range from 26 to 70 %. There is no consensus on optimal vitamin B12supplementation in postbariatric patients. The objective of this study was to compare three different regimes.
  
  
  
  In this retrospective matched cohort study, we included 63 patients with methylmalonic acid (MMA) levels ≥300 nmol/L. Group A (n = 21) received 6 intramuscular (im) vitamin B12injections including a loading dose, group B (n = 21) received 3 im vitamin B12injections without loading dose and group C (n = 21) received no im vitamin B12injections.
  
  
  
  The total post-bariatric patient population consisted of 14 males (22.2 %) and 49 women (77.8 %) with a mean current body mass index of 30.6 ± 8.0 kg/m2. There was no significant difference in vitamin B12and MMA levels between 3 groups at baseline. There was a significant difference in follow-up vitamin B12levels of group A compared to group B (p = 0.02) and group A compared to group C (p = 0.03). In the follow-up results, there is also a significant decrease in MMA levels of group A compared to group B (p = 0.02), group A compared to group C (p < 0.001), and group B compared to group C (p < 0.01).
  
  
  
  In this study, a shorter injection regime is probably not sufficient to treat a vitamin B12deficiency. An injection regime with 6 injections recovered all vitamin B12deficiencies biochemically. MMA levels cannot recover spontaneously over time without additional im injection regime.
authors.affiliation: Department of Dietetics, Catharina Hospital, Michelangelolaan 2, P.O. Box 1350, 5602 ZA, Eindhoven, The Netherlands. marieke.smelt@catharinaziekenhuis.nl.
authors.forename: H J M
authors.initials: HJ
authors.lastname: Smelt
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Pouwels
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Said
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: K A
authors.initials: KA
authors.lastname: Berghuis
authors.affiliation: Department of Clinical chemistry - Endocrinology, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: A K
authors.initials: AK
authors.lastname: Boer
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: J F
authors.initials: JF
authors.lastname: Smulders
mesh_terms: D000328:Adult; D000368:Aged; D050110:Bariatric Surgery / Q000009:adverse effects* / Q000379:methods; D016022:Case-Control Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000601:surgery*; D011183:Postoperative Complications / Q000188:drug therapy* / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000188:drug therapy* / Q000209:etiology*; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000097:blood
chemical_list: D014803:Vitamin B Complex; D008764:Methylmalonic Acid; D014805:Vitamin B 12
keywords: Bariatric surgery; Postoperative care; Supplementation; Vitamin B12