Wednesday, February 23, 2011

Nutrient deficiency and malabsorption after bariatric surgery

Nutrient Deficiency and Malabsorption after Bariatric Surgery
Nutrition and Disease
​Obesity is a growing epidemic in the United States. It is also “a major independent risk factor for the development of type 2 diabetes mellitus (T2DM) and is also associated with the rapidly increasing prevalence of diabetes” (Scheen, DeFline, DeRoover, & Paquot, 2009). Increasingly, bariatric surgeries have become a popular and effective means of inducing sustained weight loss, and is also associated with a significant improvement in glucose control and even diabetes remission (Scheen, et al., 2009). In 2008, more than 220,000 people in the United States had bariatric surgery, and Roux-en-Y gastric bypass (RYGB) surgery is the most common gastric bypass procedure (John & Hoegerl, 2009). This and numerous other bariatric procedures involve gut manipulations that alter the natural absorption of nutrients, allowing nutritional deficiencies to develop. The most common of these are vitamin B12, iron, zinc, copper, calcium, and vitamin D and can lead to secondary problems such as osteoporosis, Wernicke encephalopathy, anemia, and peripheral neuropathy (John & Hoegerl, 2009). All of these can lead to serious and even life threatening complications if left untreated.
​Anemia due to malabsorption of iron, a metallic element found in red meat and vegetables, and cobalamin (vitamin B12), found in meat and dairy products, is rather common. Iron deficiency is perhaps the most common and earliest to occur following bariatric surgery, with menstruating and pregnant females at greatest risk. Routine multi-vitamin supplementation does not appear to be sufficient to prevent iron deficiency after RYGB, and in most cases supplemental iron is necessary (Xanthakos, 2009), either orally or by intravenuous transfusion. In addition to contributing to anemia, potential complications from a vitamin B12 deficiency also extend to neuropathy and cognitive difficulties. Replacement with oral or injected forms of B12 may be necessary (John & Hoegerl, 2009). Also, Celiac disease “may be considered as an archetypal malabsorption syndrome, and it is a frequent cause of anemia without associated intestinal symptoms” (Gisbert & Gomollom, 2009).
​Along with iron absorption, zinc and copper absorption can be affected by bariatric procedures as well. Copper is a strong antioxidant essential to the human body. It is found in meat, vegetables, legumes, and whole grains. Copper deficiencies may accompany iron deficiencies. Over extended periods this can lead to progressive difficulty walking, increased muscle tone or spasticity, heart enlargement, skin changes, or neuropathy (John & Hoegerl, 2009). Copper deficiency causing anemia and neurological impairment following bariatric surgery has gained increased attention in recent years. Zinc supplementation in high doses can interfere with copper absorption (Xanthakos, 2009). Though copper deficiency is thought to be rare in developed countries, the neurologic symptoms can be profound and are frequently irreversible . “RYGB patients are routinely prescribed multivitamin-mineral preparations, iron, calcium and vitamin B12, but copper is not routinely supplemented... and little information on copper depletion after RYGB is available” (Griffith, Liff, Ziegler & Winton, 2009). As with iron deficiency, treatments include oral supplements and intravenuous transfusion therapies to restore hematological balance. Similarly, aggressive supplementation of vitamin D3 and calcium can correct deficiencies in these important nutrients as well, though the predominant source of vitamin D remains synthesis in the skin after exposure to sunlight (Xanthakos, 2009).
​In the opinion of this same researcher, Xanthakos (2009), the cause of these nutritional deficiencies in overweight and obese individuals (and, presumably, those who elect to have bariatric surgical procedures to overcome these conditions) is likely due to higher intake of relatively cheap, higher-calorie nutrient-poor processed foods. He proposes a solution in the form of a diet high in “unprocessed nutrient-dense foods including fruits and vegetables, dairy products, whole grains, nuts and legumes, and fish and protein sources which contribute the bulk of vitamins and minerals obtained from a non-supplemented diet.” In highly developed countries with an abundance of highly processed foods available and the necessity for hard physical labor in decline, it seems unsurprising that we, as a society are faced with a growing population of obese and malnourished individuals. Add to this a lifestyle rife with demands for time that precludes healthy meal planning and preparation, it is only to easy for many consumers to stop at the drive-through for their meals. With the rising medical costs associated with obesity and malnutrition, our society will increasingly be forced to address this issue and place a higher value on our nutritional health instead of convenience.


Gisbert, J.P., Gomollón, F. (2009). A short review of malabsorption and anemia. World Journal of Gastroenterology,15(37): 4644-4652. Retrieved from

Griffith, D. P., Liff, D., Ziegler, T.R., Esper, G.J., & Winton, E.F. (2009). Acquired Copper Deficiency: A Potentially Serious and Preventable Complication Following Gastric Bypass Surgery. Obesity (Silver Spring), 17(4): 827–831. doi:10.1038/oby.2008.614. Retrieved from

John S. & Hoegerl C. (2009). Nutritional deficiencies after gastric bypass surgery. J Am ​Osteopath Assoc. , 109(11): 601-4. Retrieved from: ​

Scheen, A.-J., De Flines, J., De Roover, A., & Paquot, N. (2009). Bariatric surgery in patients with Type 2 diabetes: benefits, risks, indications and perspectives. Diabetes & Metabolism, 35: 537-543. Retrieved from

Xanthakos, S.A.(2009). Nutritional Deficiencies in Obesity and After Bariatric Surgery. Pediatr Clin North Am., 56(5): 1105–1121. doi:10.1016/j.pcl.2009.07.002. Retrieved from

No comments: