Anemia is a condition in which a person doesn’t have enough healthy red blood cells. Red blood cells (RBCs) function in carrying oxygen to the tissues and they are produced in the bone marrow. Iron deficiency anemia, the most common form of anemia, develops when the body is unable to produce sufficient hemoglobin because of an iron deficiency. To read more about iron deficiency anemia, please refer to our previous blog post here.

Iron is an essential mineral that is a critical component of hemoglobin. Hemoglobin (Hg) is a four protein molecule that carries oxygen from the lung

s to the tissues. It is also important in maintaining RBC shape for proper blood flow. Each of the four globulin chains in Hemoglobin contain an iron compound called a heme. An iron atom is fixed within the heme group to give the red blood color and transport oxygen and carbon dioxide. If the body does not have enough iron, the bone marrow will not produce enough Hemoglobin which results in unhealthy RBCs.

Iron is exposed to acids in the stomach, which alters the form into a configuration that allows absorption. The Duodenum of the small intestines is the main site of iron absorption. The ileum, found at the end of the small intestinal tract, is the site of secondary absorption. Once absorbed, each plasma protein transferrin transports two atoms of iron to the liver, spleen, and bone marrow (2).

Anemia is common among patients who have undergone surgical weight loss procedures. Some weight loss procedures change the anatomy of the small intestinal tract result in malabsorption due to the restriction of food and nutrient intake. In Roux-en-Y gastric bypass (RYGB), the stomach and duodenum are completely bypassed thereby increasing the risk of iron deficiency. In the Duodenal Switch a small portion of post pyloric Duodenum is left intact to aid in iron absorption, however this may not be adequate for every individual. By redirecting the small intestinal tract in Duodenal Switch, only a small segment of the ileum is able to absorb the necessary nutrients. In both procedures however, blood tests find that patients can become iron deficient (1,3) and require oral iron supplementation or intravenous iron infusions if oral supplementation is inadequate to maintain iron levels.

Inadequate iron levels can be treated by taking iron salt supplements, especially along with vitamin C pills that help the body absorb more iron. Other types of supplements are Heme and chelated oral iron that are well tolerated without gastrointestinal upset of iron salts. For some WLS patients there may not be enough capacity for iron absorption via the GI tract and those patients may need Intravenous Iron infusions periodically. Dietary iron sources are important as a surgical weight loss patient as they are usually also high in protein (blog). Ie: Poultry, red meat, pork, seafood, eggs, beans, and green leafy vegetables are also a good source of iron.

In addition to supplementation of iron, it is important to identify any contributing factors to blood loss or decreased iron absorption such as gastrointestinal bleeding, heavy menses, surgery, pregnancy, medications or combination of supplements, infection or dietary issues. Identifying, advanced planning and/or correcting any contributing factors may reduce the iron demand for WLS patients.

In summary, iron absorption will be affected by altering the anatomy of the small intestinal tract. Although it takes a great deal of time to restore iron levels, reversing deficiency will help avoid symptoms and maintain proper blood, brain, and heart health.

Colored Coded Diagrams of where nutrients, vitamins and minerals are absorbed:
Please note this article and these diagrams are Member Exclusive Only. They are available for use by our patients ONLY. Please review your terms of use of our Member Exclusive Area.

Diagram of normal anatomy absorption here [download id=”14″].

Diagram of DS anatomy absorption here [download id=”8″].

Diagram of RNY anatomy absorption here [download id=”9″]

Written by: Mariam Michelle Gyulnazaryan & Dr. Ara Keshishian

References

1. Fincannon J. Iron deficiency after gastric bypass surgery. University of Rochester Medical Center. 2016.
2. Forth W, Rummer W. Iron absorption. Physiological Revies. 1973; 53(3) 724-792.
3. Sawaya RA, Jaffe J, Friedenberg L, Fridenberg FK. Vitamin, mineral, and drug absorption following bariatric surgery. Curr Drug Metab. 2012; 13(9) 1345-1355.
4. Von Drygalski A, Andris DA. Anemia after bariatric surgery: more than just iron deficiency. Nutr Clin Pract. 2009; 24(2) 217-226.