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  • Writer's pictureDra. Andrea Pereira

Protein, Iron and Copper Deficiency after Bariatric Surgery


It is the most frequent of the macronutrient deficiencies. Protein deficiency, a complication associated with malabsorptive surgical procedures (3-6 months after surgery), can be diagnosed by reducing blood albumin. It is related to 1% of hospitalizations after these procedures and a higher risk of infections and difficulty in wound healing.

The lack of protein causes loss of muscle mass, also associated with worse prognosis, surgical healing, increased risk of infections, and death.

Patients with this deficiency may experience symptoms of weakness, loss of muscle mass, imbalance with an increase in the number of falls, recurrent infections, hair loss and difficulty healing.

Treatment should be based on the adequacy of the oral diet and the use of protein supplements. In some cases, parenteral nutrition, which is a diet infused by vein, is necessary when there is a very severe deficiency.


Iron deficiency is one of the most common after bariatric surgery, occurring in up to 70% of patients and women of childbearing age because of menstruation, where we lose blood and, as a consequence, iron. After five years of surgery, this risk is increased due to the reduction of body iron stores due to blood loss and low intake of foods with iron. Decreased hydrochloric acid produced in the stomach and reduced overall absorption of iron in the duodenum and proximal jejunum also contribute to this deficiency.

The main clinical consequence is anemia, leading to a drop in red blood cells and ferritin, both important in the diagnosis. The most common symptoms are paleness, weakness, tiredness, increased heart rate, hair loss, and reduced performance in physical exercises and daily activities.

Treatment should include increased consumption of iron in the diet, highlighting red meat, where we have a greater amount of iron in the form to be absorbed. In the case of more severe deficiencies or in patients who do not consume red meat and/or insufficient amounts of iron in the diet, the treatment can be iron replacement in tablets or intravenously.

Even though we have iron in dark green vegetables and other vegetables, its absorption is not as effective. Some people cook food with nails, screws, or iron pieces, but this does not help improve iron deficiency anemia.

Associating vitamin C and fructo-oligosaccharides with iron supplementation can prevent constipation, which is one of the adverse effects of iron replacement, improving intestinal flora and the absorption of this mineral.

In addition, iron absorption is impaired in cases of copper deficiency, so we must evaluate this micronutrient in the case of iron deficiencies that do not improve with treatment.


Copper is an essential coenzyme for blood formation and central nervous system functions. Annual evolution of the serum copper level is suggested for patients after bariatric surgery and a more rigorous follow-up when they present anemia, drop in white blood cells, neurological symptoms or wound healing problems. On average, 10% of patients after surgery have this deficiency, and most cases are asymptomatic.

Copper deficiency can be caused by zinc supplementation due to competition for the same absorption area and the reduction of its absorption caused by surgery and the consumption of foods rich in copper due to intolerances. The main symptoms are anemia, a drop in white blood cells and other cells produced by the bone marrow. In the most severe cases, we may have reduced pigmentation of the skin, hair, and nails, tingling, weakness, and pain in the legs and arms.

Copper participates in the absorption of iron, both in the intestinal cell and in the bone marrow, so when this element is deficient, iron absorption through the oral or venous route is impaired. Therefore, we should investigate copper levels in iron deficiencies that do not respond to treatment.

Oral copper replacement is the most common treatment for this problem.

Don't wait to have these symptoms to seek help. See your doctor and get tested annually after bariatric surgery. Follow-up is critical before and after surgery to prevent nutritional deficiencies and weight gain.

Dr. Andrea Pereira, MD, PhD


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