Iron and Bariatric Surgery

Iron is a mineral in our bodies that helps maintain the health of our blood. Iron is a component of hemoglobin, a protein in our red blood cells. Red blood cells are responsible for carrying oxygen from the lung to other parts of the body. If we don’t have enough iron in our blood, red blood cells can’t effectively transport oxygen, therefore depriving our tissues of energy. This can cause complications in our lungs, muscles, and brain; this is why it is important we eat enough food. Iron is also important in cellular functioning, hormone synthesis, and neurological development. Iron is stored in our body as a blood protein called ferritin, mainly in our liver, spleen, muscle, and bone marrow. This is a common way to test for iron deficiency, though a doctor may also test levels of transferrin, which is a protein that binds to iron for transport to tissues. Iron is important for many different roles in the body and it is of special importance after bariatric surgery.

Iron is found naturally in many foods and comes in two forms: heme and non-heme. Heme iron is found only in animal foods such as red meat, poultry, and seafood. Organ meats, like liver, are particularly high in iron. Non-heme sources of iron are found in plant foods such as whole grains, nuts, seeds, legumes, and leafy greens. Many breakfast cereals are fortified with iron to help increase our iron intake. Heme iron is more bioavailable than non-heme, which means that it is absorbed more efficiently by the body. This is because when we eat meat, we are eating the blood proteins and hemoglobin that are in the body of the animal. Absorption of heme iron is at a rate of about 15-35%, while non-heme sources are thought to be absorbed closer to 2-20%. Therefore, vegetarians and people who don’t eat animal products on a regular basis may need to consume twice as much iron throughout the day.

Several nutrients may help or hurt the absorption of iron. Vitamin C increases the absorption of non-heme iron from plant sources. This is why many iron supplements also contain vitamin C. This vitamin is found in several fruits and veggies such as citrus, strawberries, bell peppers, and broccoli. This is why meal balancing is especially important in making sure we are eating all of the essential nutrients our body needs to function. Calcium, on the other hand, has been found to inhibit iron absorption, as they compete for the same receptors in cells. Many health experts recommend avoiding taking iron supplements along with foods that are high in calcium, such as dairy, leafy greens, tofu, sardines, and salmon.

Daily iron needs vary depending on the person and their health. Adult men need about 8 milligrams (mg) per day; premenopausal women need about 18mg per day (after menopause, only 8g per day); and pregnant women need almost 30mg of iron per day. Women are generally at higher risk for iron deficiency due to blood loss from menstruation (this is why women need less iron after menopause). About 1 in 5 women have iron deficiency anemia, which is why it is important to eat plenty of iron-rich foods every day.

Below are the iron contents of various iron-rich foods:

  • Lentils, 1 cup boiled (7mg)
  • Beef liver, 3oz (5mg)
  • Tofu, ½ cup (3mg)
  • Cashews, 1 oz roasted (2mg)
  • Broccoli, 1 cup raw (1mg)

Eating a well-balanced diet is the best way to make sure you are getting plenty of iron every day and prevent iron deficiency. This is a type of anemia in which the body does not have enough healthy red blood cells, as the lack of iron causes a decrease in hemoglobin. This means the body’s ability to carry oxygen to tissues is impaired, which can lead to symptoms such as fatigue, pale skin, shortness of breath, cold hands and feet, brittle nails, and weakness. In some cases, a person may develop a condition called pica, in which a person has cravings for non-food items such as dirt, starch, and ice (chewing ice is a common sign of iron deficiency anemia). Iron deficiency anemia can be caused by low intake of iron, especially for people who avoid heme iron, such as vegans and vegetarians. This type of anemia is also common after bariatric surgery since most iron absorption happens in the duodenum – the first part of the small intestine which is bypassed in some types of bariatric surgery.

If a person suspects iron deficiency, their doctor can test iron levels through several different tests. Serum ferritin measures the amount of iron stored in the body, while serum iron tests the amount of iron in the blood. When iron stores are low, the body will pull the iron out of stores for use in red blood cells. Based on one or more of these tests, a doctor or other health professional may recommend an iron supplement. Most patients who have had bariatric surgery are advised to take a supplement even if their iron is not low to prevent anemia, since their body does not absorb iron the way it did before surgery. After surgery, it is very important to make sure you are eating a well-balanced diet to maintain nutrient intake. A dietitian can help you make sure you are eating plenty of vitamins and minerals throughout the day; a good rule of thumb is to use the plate method for portion sizing and make sure you are eating lots of fruits and vegetables.


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Chloe Seddon is a registered dietitian nutritionist who holds a Master’s Degree in health promotion from the University of Connecticut. She specializes in nutritional counseling, with a focus on a non-dieting approach to maintain healthy weight and goal-oriented lifestyle changes for long term success. She teaches intuitive eating and easy meal preparation to help clients sort through the myriad of nutritional misinformation to focus on having a balanced and happy relationship with food. She counsels clients with a range of issues, including chronic disease management, sports nutrition, disordered eating and weight loss. Chloe currently works as a nutritional counselor and educator providing group and individual consulting. She believes that balancing food, eating and exercise should be enjoyable and healthful.

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