Raising the Standard: Why is Iron Deficiency Such a Problem after Bariatric Surgery and What Can Be Done?

| March 1, 2019 | 0 Comments

by Dominick Gadaleta, MD, FACS, FASMBS, and Sameera Khan, RD, PA-C,MBA

Dr. Gadaleta is Chair of the Department of Surgery at Southside Hospital and Director of Metabolic and Bariatric Surgery at North Shore University Hospital, Northwell Health in Manhasset, New York; and Associate Professor of Surgery at Zucker School of Medicine at Hofstra/Northwell in Hempstead, New York. Ms. Khan is the Bariatric Program Coordinator at North Shore University Hospital in Manhasset, New York.

Bariatric Times. 2019;16(3):24.

This column series explores the ongoing strive for quality excellence in the field of bariatric surgery.

Column editors
Anthony T. Petrick, MD, FACS, FASMBS
Quality Director, Geisinger Surgical Institute; Director of Bariatric and Foregut Surgery, Geisinger Health System, Danville, Pennsylvania

Dominick Gadaleta, MD, FACS, FASMBS
Chair, Department of Surgery, Southside Hospital; Director, Metabolic and Bariatric Surgery, North Shore University Hospital, Northwell Health, Manhasset, New York; Associate Professor of Surgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York

Iron deficiency is tightly linked to adipose tissue inflammation associated with obesity, involving impaired absorption of iron in the duodenum along with elevated hepcidin levels. Low iron status in individuals with obesity might result from nutritional (lowered absorption) as well as functional (higher sequestration) iron deficiency.1

Proper selection of the suitability of candidates for bariatric surgery involving adequate nutritional assessment and dietary guidance are essential when preparing the patient for surgery and achieving optimal surgical outcomes. Iron deficiency anemia is a long-term problem common after bariatric surgery. While studies on the preoperative micronutritional status of a patient have widely indicated low iron and ferritin serum concentrations, postoperative causes, such as anatomical changes after surgery, increased iron requirements, reduced acid production in the stomach, use of drugs to suppress gastric acid secretion, and aversion to certain foods, exacerbate the deficiency. 

When adhering to the guidelines of the American Society for Metabolic and Bariatric Surgery (ASMBS), iron status should be evaluated at the patient’s follow-up visit after bariatric surgery. Routine supplementation to prevent iron deficiencies are 45 to 60mg elemental iron per day, or 150 to 200mg elemental iron supplements per day in case of deficiencies.2 Vitamin C supplementation can be concurrently prescribed to increase iron absorption. According to the recommended dietary allowance (RDA), 90mg of vitamin C for men and 75mg or more of vitamin C for females is recommended. It is also recommended to separate the intake of calcium supplements from iron intake. 

There are two forms of iron in food: heme and non-heme. While heme iron comes from animal foods and is the most absorbed, non-heme iron is plant based and has a limited absorption of 30 to 60 percent of the total iron serving.

Due to the underlying mechanism of iron absorption being impaired through the gut, oral supplementation of iron is frequently insufficient, meaning intravenous iron is necessary, particularly in patients who undergo bariatric surgery.

Studies suggest liver biopsies were performed in all patients, and if no signs of hemosiderosis were seen, prophylactic parenteral infusions of iron were given periodically, in addition to oral iron supplementation.3 Early parenteral supplementation was provided during the first postoperative year with the first signs of iron deficiency before it developed to anemia.

Lab work should include iron panel, ferritin level, C-reactive protein (CRP), and total iron binding capacity (TIBC). Vitamin and mineral status assessments should be conducted every three months during the first year after surgery, every six months during the second year, and annually thereafter.2 Recent evidence suggest the effects of inflammation on iron nutrition can be assessed by measuring a patient’s CRP level. A level of more than 3mg/L of CRP denotes inflammation, which in turn leads to a ferritin level likely to be consistent with the diagnosis of iron deficiency.1


  1. Cepeda-Lopez AC, Allende-Labastida J, Melse-Boonstra A, et al. The effects of fat loss after bariatric surgery on inflammation, serum hepcidin, and iron absorption: a prospective 6-mo iron stable isotope study. Am J Clin Nutr. 2016;104(4):1030–1038.
  2. Sherf Dagan S, Goldenshluger A, Globus I, et al. Nutritional recommendations for adult bariatric surgery patients: clinical practice. Adv Nutr. 2017;8(2):382–394.
  3. Salgado Wilson Jr, Modotti C, Nomino CB, Ceneviva R. Anemia and iron deficiency before and after bariatric surgery. Surg Obes Relat Dis. 2014;10(1):49–54.   

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Category: Past Articles, Raising the Standard

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