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Gastric Bypass: Iron Deficiency

Iron deficiency can be a problem following Gastric Bypass because iron is partially absorbed in the duodenum. The duodenum is bypassed along with the stomach. Iron deficiency can be a particular problem for women who lose blood (and thus iron) with their menses.

We recommend that all gastric bypass patients eat foods that are high in iron, and that iron and hemoglobin levels be checked once or twice a year. For menstruating women we suggest a daily iron supplement such as ferrous sulfate or ferrous gluconate 300 to 350mg per day.

Iron absorption seems to be enhanced by adequate Vitamin C intake. We suggest that all patients take a full potency multivitamin daily. Most multivitamins contain about 60mg Vitamin C. This should be adequate under normal conditions. When one is iron deficient and trying to replace iron stores, increasing Vitamin C intake to 500mg per day may be helpful.

Iron containing foods:

  • Organ meats such as liver
  • Meat, fish, and poultry
  • Shellfish, especially oysters
  • Dried beans and peas
  • Whole-grain products such as breads and cereals
  • Dark-green leafy vegetables such as spinach and broccoli
  • Dried fruits such as figs, raisins, apricots, and dates


Related Medical Journals & Articles

Prophylactic iron supplementation after Roux-en-Y gastric bypass: a prospective, double-blind, randomized study.

Brolin RE, Gorman JH, Gorman RC, Petschenik AJ, Bradley LB, Kenler HA, Cody RP

OBJECTIVE: To determine whether prophylactic oral iron supplements (320 mg twice daily) would protect women from iron deficiency and anemia after Roux-en-Y gastric bypass. DESIGN: Prospective, double-blind, randomized study in which 29 patients received oral iron and 27 patients received a placebo beginning 1 month after Roux-en-Y gastric bypass. SETTING: Tertiary care medical center. PATIENTS AND INTERVENTIONS: Complete blood cell count and serum levels of iron, total iron binding capacity, ferritin, vitamin B12, and folate were determined preoperatively and at 6-month intervals postoperatively in 56 menstruating women who had Roux-en-Y gastric bypass. MAIN OUTCOME MEASURE: Incidence of iron deficiency and other hematological abnormalities in each treatment group. RESULTS: Hemoglobin, hematocrit, and vitamin B12 levels were significantly decreased compared with preoperative values in both groups. Conversely, folate levels increased significantly over time in both groups. Oral iron consistently prevented development of iron deficiency in the iron group. Ferritin levels did not change significantly in the iron group. However, in placebo-treated patients, ferritin levels 2 years postoperatively were significantly decreased compared with preoperative levels. There was no difference in the incidence of anemia between the 2 groups. However, the incidence of microcytosis was substantially greater (P=.07) in placebo-treated than iron-treated patients.

CONCLUSIONS: Prophylactic oral iron supplements successfully prevented iron deficiency in menstruating women after Roux-en-Y gastric bypass but did not consistently protect these women from developing anemia. On the basis of these results we now routinely recommend prophylactic iron supplements to menstruating women who have Roux-en-Y gastric bypass.

Arch Surg 1998 Jul;133(7):740-4

Iron absorption and therapy after gastric bypass.

Rhode BM, Shustik C, Christou NV, MacLean LD.

Department of Surgery, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.

Iron deficiency anemia is a common complication of gastric bypass. The authors assessed the value of taking vitamin C with oral iron in correcting deficiencies in iron stores and anemia postoperatively. MATERIALS AND METHODS: Iron absorption tests were performed on 55 patients 3.2+/-2.0 years after isolated gastric bypass to identify those at higher risk for the late development of anemia. Twenty-nine of this group agreed to a therapeutic trial of iron alone or with vitamin C over a 2-month period. All 55 patients were followed up for 27.1+/-1.0 months following the study. RESULTS: The iron absorption test identified patients with low iron stores, as indicated by low serum ferritin, and those with sufficient absorption surface to benefit from oral iron. The addition of vitamin C appears to enhance the therapeutic effect of iron by correcting ferritin deficits (P < 0.01) and anemia (P < 0.05). Differences in intestine length bypassed by the operation (10 vs. 100 cm) did not affect late ferritin and hemoglobin values.

CONCLUSION: This study suggests but does not prove that the addition of vitamin C to iron therapy after gastric bypass is more effective in restoring ferritin and hemoglobin than iron alone. These results are in contrast with the outcome 22.8 months later, when approximately 50% of study patients were again anemic. Closer follow-up of patients is urgently needed.

Obes Surg 1999 Feb;9(1):17-21

The role of vitamins in the prevention and control of anaemia.

Fishman SM, Christian P, West KP.

Division of Human Nutrition, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205, USA.

OBJECTIVE: While iron deficiency is regarded as the major cause of nutritional anaemia, changes in vitamins A, B12, C and E, folic acid and riboflavin status have also been linked to its development and control. This paper provides a systematic review of vitamin supplementation trials relating to the control of nutritional anaemia. METHODS: A MEDLINE search was used to find reports of vitamin supplementation trials that reported changes in anaemia or iron status. RESULTS: Vitamin A can improve haematological indicators and enhance the efficacy of iron supplementation. Both folate and vitamin B12 can cure and prevent megaloblastic anaemia. Riboflavin enhances the haematological response to iron, and its deficiency may account for a significant proportion of anaemia in many populations. Vitamin C enhances the absorption of dietary iron, although population-based data showing its efficacy in reducing anaemia or iron deficiency are lacking. Vitamin E supplementation given to preterm infants has not reduced the severity of the anaemia of prematurity. Vitamin B6 effectively treats sideroblastic anaemia. Multivitamin supplementation may raise haemoglobin (Hb) concentration, but few studies have isolated the effect of multivitamins from iron on haematological status.

CONCLUSIONS: In general, the public health impact of vitamin supplementation in controlling anaemia is not clear. Neither are the complex interactions involving multiple vitamins in haematopoiesis sufficiently understood to explain the observed variability in haematological responses to vitamins by age, population, vitamin mixture and dosages. Further research is needed to understand the roles of individual and combined vitamin deficiencies on anaemia to design appropriate micronutrient interventions to prevent anaemia.

Public Health Nutr 2000 Jun;3(2):125-50

[Please note: This is a very broad review article dealing with many causes of anemia. The people studied in the papers covered by this review were not gastric bypass patients. So while the review is interesting it may or may not apply to gastric bypass patients. CDC]

Are any oral iron formulations better tolerated than ferrous sulfate?

- Clinical inquiries: from the family practice inquiries network

Todd McDiarmid, E. Diane Johnson

EVIDENCE-BASED ANSWER Ferrous salt preparations (ferrous sulfate, ferrous gluconate, and ferrous fumarate) are equally tolerable. (Grade of recommendation: A, based on randomized controlled trial.) Controlled-release iron preparations cause less nausea and epigastric pain than conventional ferrous sulfate (grade of recommendation: A, based on randomized controlled trials), although the discontinuation rates between the 2 iron formulations were similar. Ferrous sulfate remains the standard first-line treatment of iron-deficiency anemia given its general tolerability, effectiveness, and low cost.

EVIDENCE SUMMARY A randomized, double-blinded, placebo-controlled study in 1496 subjects examined side-effect rates of 3 iron salt formulations using equal dosages of elemental iron (Table). (1) Gastrointestinal (GI) side-effect rates were not significantly different. The side-effect rate in the ferrous sulfate group (23%) was significantly different from that of the placebo group (14%); thus, for every 11 patients treated with ferrous sulfate, 1 patient would have GI side effects attributable to the iron salt (number needed to harm [NNH] = 11).

Two formulations--controlled-release iron preparations and polysaccharide-iron complexes--decrease the amount of iron presented to the proximal GI tract. Three large randomized trials assessed tolerability of controlled-release iron preparations compared with ferrous sulfate. (2-4) The only double-blinded study found a lower rote of nausea and epigastric pain in the controlled-release iron formulation among 1376 blood donors receiving 200 mg/day elemental iron (3.3% vs 6.4%, P < .05, NNH = ~32). (2) A nonblinded randomized trial of 543 nonanemic adult patients taking 50 mg/day elemental iron also found a lower rote of stomach-related side effects in the controlled-release group (12.2% vs 27.2%, P < .001, NNH = ~7). (3) However, none of the 3 studies showed a difference in the discontinuation rates between the 2 iron formulations. Comparative constipation rates among the trials were conflicting.

Journal of Family Practice, June, 2002


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