Multicentre randomized controlled trial to evaluate the optimal treatment for patients who developed an iron deficiency after Roux-en-Y Gastric bypass.

Morbid obesity is worldwide a still growing problem. The number of bariatric procedures are still increasing with 9000 bariatric operations in 2009. The golden standard is the Roux-en-Y Gastric bypass (RYGB). The RYGB ensures an excess weight loss of 60-70% in our hospital.

Unfortunately vitamin and mineral deficiencies are a consequence from RYGB. Iron deficiency occurs in 14-66% in the first two years after surgery. Worldwide there are three most used options of treatment for this: treatment with ferrous fumarate, ferrous gluconate and intravenous injection of Ferinject.

Our goal is to determine which treatment is the most effective to normalize ferritin values in the blood and which treatment is the most cost-effective one after a RYGB.

Inclusion Criteria:

• all women who underwent a Roux-en-Y gastric bypass and developed an iron deficiency postoperatively (ferritin<20microgram/L)

Exclusion Criteria:

• iron deficiency peroperative, blood transfusions during study period, iron containing nutritional supplements except the standard multivitamins after bariatric surgery, decreased renal failure, excessive blood loss due to menstruation, anemia not caused by iron deficiency, accumulation of iron, hypersensitivity for noe of the medicinal products, psychiatric illness, pregnancy