Influence of diet and supplements on iron status after gastric bypass surgery

Background: Iron deficiency is common after Roux-en-Y gastric bypass (RYGB) surgery, but there is no consensus on the optimal diet quality and quantity for restoring and preserving iron status. Objectives: The authors explored the impact of dietary and supplemental sources of iron and absorptive factors on iron status. Setting: Academic, United States. Methods: In a cross-sectional cohort of individuals who underwent RYGB, nutrient intakes from food and supplements were measured using 3-day food records. Blood biomarkers of iron status, including concentrations of ferritin, total iron binding capacity, serum transferrin receptor (sTfR), and the sTfR:ferritin ratio, were assessed by a reference laboratory; iron deficiency was defined as having at least 2 abnormal measures. Associations between iron status biomarkers and dietary predictors were determined using regression analysis. Results: Of the 36 participants, 97% were female, the mean age was 45 years (95% confidence interval, 41-48 years), and body mass index was 32 (30-35) kg/m(2). Iron deficiency was found in 42% of participants. Dietary intake of heme iron, found in meats, was favorably associated with 3 iron status biomarkers (ferritin, beta = .366; sTfR:ferritin ratio, beta = .459; and total iron binding capacity, (beta = 18.26; all P < .05), independent of obesity-induced inflammation. Intake of vitamin C from food contributed to iron status (ferritin, = .010 and sTfR:ferritin ratio, (beta = -.011; P < .05). Use of supplementary non-heme iron, at doses recommended for prophylaxis (45 mg/d), was positively associated with serum ferritin (beta = .964; P = .029). Conclusions: For patients who have undergone RYGB, consuming high, but realistic amounts of heme iron in meat, vitamin C from food, and adherence to recommended iron supplements can prevent iron deficiency. (C) 2016 American Society for Metabolic and Bariatric Surgery. All rights reserved.