An optimized multivitamin supplement lowers the number of vitamin and mineral deficiencies three years after Roux-en-Y gastric bypass: a cohort study

Surg Obes Relat Dis. Mar-Apr 2016;12(3):659-667. doi: 10.1016/j.soard.2015.12.010. Epub 2015 Dec 10.


Background: Vitamin and mineral deficiencies are common after Roux-en-Y gastric bypass (RYGB) surgery. In particular, inadequate serum concentrations of ferritin and vitamin B12 have been found in 11% and 23% (respectively) of patients using a standard multivitamin supplement (sMVS) 1 year after RYGB.

Objective: To evaluate the effectiveness and safety of Weight Loss Surgery (WLS) Forte® (a pharmaceutical-grade, optimized multivitamin supplement) compared with an sMVS and a control group (nonuser) 3 years after RYGB.

Setting: General hospital specialized in bariatric surgery.

Methods: A follow-up cohort study of a triple-blind randomized, controlled clinical trial.

Results: At baseline 148 patients were enrolled (74 [50%] in the sMVS group and 74 [50%] in the WLS Forte group). After a mean follow-up of 36 months, 11 (7%) patients were lost to follow-up, of whom 2 were secondary to death. At the end of the study, 11 (17%) patients in the WLS Forte and 17 (24%) in the sMVS group stopped using a supplement. In addition, 64 (47%) patients were using WLS Forte and 45 (33%) patients a sMVS. Patient characteristics and follow-up length were comparable between the groups. Significantly more patients were diagnosed with anemia (16% versus 3% [P = .021]), a ferritin deficiency (14% versus 3% [P = .043]), and a zinc deficiency (8% versus 0% [P = .033]) in the sMVS group compared with WLS Forte. Five patients developed a vitamin B12 deficiency while using WLS Forte, versus 15 of sMVS users (P = .001). No adverse events occurred that were related to supplement use.

Conclusion: At 3 years postoperative of RYGB, an optimized multivitamin supplement (WLS Forte) was more effective in reducing anemia and ferritin, vitamin B12, and zinc deficiencies compared with a standard supplement and control.

Keywords: Bariatric surgery; Deficiency; Dietary supplements; Gastric bypass; Malnutrition; Minerals; Vitamins.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Avitaminosis / prevention & control*
  • Dietary Supplements*
  • Female
  • Ferritins / deficiency
  • Follow-Up Studies
  • Gastric Bypass / adverse effects*
  • Humans
  • Male
  • Malnutrition / prevention & control
  • Obesity, Morbid / surgery
  • Postoperative Complications / prevention & control
  • Trace Elements / deficiency*
  • Vitamins / administration & dosage*


  • Trace Elements
  • Vitamins
  • Ferritins