1 Effect of Two Bariatric Procedures on Macro- and Micronutrient Levels Inspite of Multivitamin Supplementation Mohammed Matar, MD, FACS, Ahmed Shoka, MD, MRCS Department of General Surgery, Ain Shams University, Cairo, Egypt Abstract Background: Bariatric surgery is proving to be an effective means of allowing sustained weight loss as compared to alternative strategies especially for patients with body mass index (BMI) >35kg/m 2 . Consequent alterations in micronutrient absorption may lead to undesired metabolic side effects. Objective: To compare changes in nutritional status after 2 bariatric surgical techniques in a period of 24 months. Patients and methods: A prospective double armed randomized clinical trial was conducted at the Surgical Department of Ain Shams University hospitals. 69 obese subjects (BMI >35kg/m 2 ) were allocated to either vertical sleeve gastrectomy (VSG) as group 1 or mini-gastric bypass (MGBP) as group 2. All patients were supplemented with multivitamins and mineral preparations postoperatively. The patients were examined before surgery and then every three months during the first year & bi-annually during the second postoperative year. Clinical data collected at 3, 9, 18 and 24 months were tabulated and analyzed. Results: Out of 69 surgically treated patients, 67 completed the 2 year follow- up period. The BMI was lower at 3, 9 & 18 months postoperative in MGBP group compared to the VSG group, but only showed statistical significance at 24 months visit. By the end of 3 months, percentage of excess weight loss (%EWL) was statistically significantly higher in the MGBP versus the VSG. Comorbidities were collectively reduced in both groups. Microcytic anemia, as reflected by low mean hemoglobin concentration and higher mean serum