Iron ( F so 4 ) Bioavailability in Obese Subjects Submitted to Bariatric Surgery

Objective: To determine iron bioavailability in obese subjects after the ingestion of a nutritional supplement containing multiple nutrients. Methods: Fourteen persons were studied before and after bariatric surgery after the ingestion of a nutritional formulation containing 25 mg iron, 25 g fiber and 800 mg calcium. Serum iron levels were measured basally and every hour after the ingestion of 200 mL of the formulation, and serum ferritin, unsaturated iron binding capacity (UIBC), hemoglobin, albumin, total proteins, total triglycerides, total cholesterol and fractions (LDL-cholesterol and HDL-cholesterol) sere determined at the same time points. Results: The following ferremia values (median and minimum maximum) were obtained before and after bariatric surgery, respectively: Fasting, 105 (70 364) μg/dL and 198 (38 617) μg/dL; 1 hour, 103 (63 305) μg/dL and 160 (11 207) μg/dL; 2 hours, 103 (62 150) μg/dL and 141 (10 412) μg/dL; 3 hours. 97 (63 190) μg/dL and 153 (6 270) μg/dL; 4 hours, 91 (58 163) μg/dL and 156 (40 251) μg/dL (p>0.05), with no association of serum iron levels with time. There was a difference in total triglycerides (95 ± 29 mg/dL and 60 ± 10 mg/dL) which were correlated with a decrease in serum ferritin levels (r = 0,926, p = 0.008), UIBC (r = 0.910, p = 0.01), total cholesterol (r = 0,918, p = 0.01) and LDL-c fraction (r = 0.830, p = 0.04), with an increase in HDL-c fraction (r = 0,807, p = 0.05). Conclusion: Iron bioavailability in obese subjects was affected by the ingestion of the nutritional formulation containing calcium and fiber and the serum ferritin and UIBC values involved in the body metabolism of iron were reduced by the surgery, a fact that may cause these patients to develop iron deficiency.