Prevalence of iron, folate, and vitamin B12 deficiency anemia after laparoscopic Roux-en-Y gastric bypass

Obes Surg. 2008 Mar;18(3):288-93. doi: 10.1007/s11695-007-9310-0. Epub 2008 Jan 23.


Background: One of the most common bariatric operations is the laparoscopic Roux-en-Y gastric bypass (LRYGBP) in which the gastric capacity is restricted and the absorption by the small intestine is reduced. The objective of this study was to evaluate the incidence of iron, folate, and vitamin B12 deficiency anemia in patients undergoing LRYGBP.

Patients and methods: Clinical records of 30 patients who underwent LRYGBP between July 2003 and January 2005 and had a minimum follow up of 24 months at our outpatient clinic were included. Multivitamin supplementation was prescribed to all patients. The complete blood cell count, plasma iron, total iron-binding capacity, transferrin saturation, serum folate, and cobalamin levels before surgery, 6 months, 1, 2, and 3 years after the surgery were analyzed.

Results: There were 25 women (83.4%) and five men (16.6%) with ages from 21 to 56 years. Before surgery, two patients (6.6%) presented ferropenic anemia. Iron deficiency was seen in 40 and 54.5% 2 and 3 years after surgery, respectively. Cobalamin deficiency was observed in 33.3% at 2 years and in 27.2% at 3 years. At 2-year follow-up, 46.6% of the patients had already developed anemia and 63.6% at 3 years. Folate deficiency was not observed in any patient.

Conclusion: Our routine scheme of vitamin supplementation is not sufficient to prevent iron and vitamin B12 deficiencies in most patients.

MeSH terms

  • Adult
  • Anemia / etiology*
  • Anemia / prevention & control
  • Anemia, Iron-Deficiency / etiology*
  • Anemia, Iron-Deficiency / prevention & control
  • Dietary Supplements
  • Female
  • Folic Acid Deficiency / etiology*
  • Folic Acid Deficiency / prevention & control
  • Gastric Bypass / adverse effects*
  • Humans
  • Laparoscopy*
  • Male
  • Middle Aged
  • Obesity, Morbid / blood
  • Obesity, Morbid / surgery*
  • Vitamin B 12 Deficiency / etiology*
  • Vitamin B 12 Deficiency / prevention & control
  • Vitamins / administration & dosage


  • Vitamins