Malabsorption and micronutrient deficiencies are known problems after bariatric surgery. Therefore, supplementation and regular controls are inevitable. Iron (Fe2+), vitamin B12 and folic acid levels, which may be disrupted after bariatric procedures, are suspected to depend on gastric pH levels.


All patients who underwent SG between 2008 and 2013 were enrolled in our follow-up program. The patients were examined preoperatively and then four times during the first year. Fe2+ metabolism and weight parameters were monitored. All the patients received one multivitamin tablet daily. All the parameters were then analyzed for associations with PPI intake.


Data of 385 out of 400 (96.2%) patients were analyzed after 1 year of follow-up (3.8% lost to follow-up). Thirty-nine (10.1%) patients took PPI for at least three months during the first year. The Fe2+ levels were significantly lower (p = 0.002) in the PPI group in comparison to the non-PPI group. Vitamin B12 levels also showed significant differences (p= 0.04), while there were no significant differences for folic acid (p=0.3).


Our data show that higher gastric pH levels caused by PPI intake negatively influence Fe2+ absorption. Therefore, Fe2+ metabolism parameters and red blood cell account, as well as vitamin B12 and folic acid, should be monitored, especially in patients receiving PPI therapy after SG.