Iron Deficiency after Bariatric Surgery

Chewing Ice: Is that an Iron Deficiency?

By Heather Mackie, MS, RD, LD

Have you ever found yourself stopping at a fast food establishment for a cup of ice? Maybe this happens a couple times throughout the day? Many bariatric patients report this behavior after their bariatric surgery. While chewing ice does not necessarily mean you have low iron levels, it does warrant getting your iron levels checked.

Iron’s Role. Iron is a key element in the metabolism of all living organisms and helps to make up hundreds of proteins and enzymes. Iron has many functions, but below are some of the key functions of iron.

  • Heme is the iron-containing compound found in molecules. • Hemoglobin and myoglobin are heme-containing proteins that help to transport and store oxygen.
  • Hemoglobin is the primary protein in red blood cells and makes up two-thirds of the body’s iron. It helps to transport oxygen from the lungs to the rest of the body.
  • Myglobin transports and stores oxygen (short-term) for muscle cells. This is extremely important when the muscles are working (such as in an physical activity session).
  • Iron is involved in electron transport (synthesizes a compound called ATP, which is the primary energy storage compound in cells) and energy metabolism.
  • Iron acts as an antioxidant.
  • Iron assists with DNA synthesis.

Symptoms of Iron Deficiency. There are many symptoms related to iron deficiency including fatigue (low energy levels), increased heart rate (especially during physical activity session), heart palpitations (especially during a physical activity session), rapid breathing on exertion, decreased athletic and physical work capacity, the inability to maintain a normal body temperature, brittle and spoon-shaped nails, sores at the corners of the mouth, taste buds diminish (are not as sensitive), sore tongue, some forms of hair loss, pica (the eating of non-food substances, such as clay, cornstarch or the chewing of ice), and a lower immune status (the increased ability to catch a cold or get sick). Some other symptoms of iron deficiency include dry, scaling, cracking skin; itchy skin; confusion; headaches; decreased mental capacity; amnesia; irritability; restless leg syndrome; dizziness; and depression. If iron deficiency continues and is advanced it can lead to difficulty swallowing due to the formation of webs of tissue in the throat and esophagus.

How Much Iron? The recommended dietary allowance (RDA) was developed for the general, healthy population and these recommendations do not always apply to bariatric surgery patients. Males (all ages) and females greater than 51 years of age require 8 milligrams (mg) of iron per day. Females aged 19-50 require 18 mg of iron per day. However, bariatric surgery patients have varied needs. Some patients only require 18 mg per day, while others may require as much as 100 mg or more per day. It is very important to get your personal iron status checked via blood work so your bariatric surgeon or primary care physician can determine your individual iron recommendation.

Why do Bariatric Patients Require More Iron? There are several reasons as to why bariatric surgery patients require more iron following bariatric surgery than prior to bariatric surgery.

  • As many as 35-44% of pre-op bariatric patients have low iron levels prior to their bariatric surgery.
  • There is less stomach acid following bariatric surgery and iron needs acid to aid in its absorption.
  • Post-operatively, about 20-50% of patients experience an iron deficiency and the risk increases over time. One study reported half of the patients were getting the recommended amount of iron and were still deficient, which further explains the need for individualized recommendations and continued blood work.
  • A daily multivitamin may not prevent an iron deficiency since so many patients require above and beyond what is included in their daily multivitamin.
  • Keep in mind the risk of iron deficiency increases over time as the body eventually runs out of iron stores.
  • If you chose gastric bypass, then the primary area of absorption for iron was bypassed and this further increases your need for iron supplementation. This same area is also bypassed in the duodenal switch.
  • Post-operatively, there may be incomplete digestion of protein and many patients have an aversion to iron-rich foods, such as red meat. Red meat tends to be one of the top five foods that bariatric patients do not tolerate very well (although every patient is different in what they do and do not tolerate following their bariatric surgery).
  • There is decreased absorption of iron in gastric bypass and biliopancreatic diversion with or without duodenal switch.
  • As many as 25-50% of bariatric surgery patients develop an iron deficiency and often this happens within 6-9 months following bariatric surgery, although it may take 3-4 years to develop.

Maintenance Level/Daily Dose vs. Waiting. Of course you should always follow the instructions of your bariatric surgeon, but it should be explained why some bariatric surgeons have patients start iron immediately following their bariatric surgery while others do not. Remember, your bariatric surgeon knows your individual medical history and blood work. This article is intended as general information and is not intended to provide medical advice. There are two schools of thought when it comes to iron supplementation following bariatric surgery. Some bariatric surgeons prefer to monitor lab levels and then have patients start iron once their iron levels start to drop, while others prefer to have patients start a daily dose of iron shortly after their bariatric surgery in order to prevent levels from dropping. Either way, the most important thing is to continue to get your blood work done as recommended so your iron supplementation can be adjusted as needed and you can maintain normal iron levels, leaving you feeling energized and healthy.

Iron Laboratory Studies. It is important to get your iron levels checked in the morning while you are fasted, as levels can change throughout the day. While ferritin is the normal lab parameter for iron in the general population, it may not be the best parameter for bariatric patients. Typically ferritin is a sign that iron stores are dropping and is normally touted as the primary sign of iron deficiency. However, ferritin is also an indicator of inflammation and obesity is a disease of inflammation. There are three levels of iron deficient states described below.

  1. Anemia is characterized by low serum iron levels, low MCV (mean corpuscular volume) levels, high TIBC (total iron binding capacity) levels, and high transferrin levels.
  2. Depletion is characterized as a serum iron between 60-115 micrograms (mcg)/deciliter (dL) and a TIBC between 360-390 mcg/dL.
  3. Iron deficiency anemia is characterized as a low MCV, low MCH (mean corpuscular hemoglobin), low hematocrit, low hemoglobin, a serum iron less than 40 mcg/dL, a ferritin less than 10 nanograms (ng)/milliliter (mL), a TIBC greater than 390 mcg/dL, and a transferrin less than 15%.

Keep in mind iron depletion means that iron stores are depleted, but there is no change in the functional iron supply yet. Early functional iron deficiency means that the supply of functional iron is low enough to impair red blood cell formation, but there is not a state of anemia yet. Iron deficiency anemia means there is inadequate iron to support normal red blood cell formation (the ones formed will be smaller and have less hemoglobin), which means there will be inadequate oxygen delivery and/or a suboptimal function of iron-dependent enzymes.

Food Sources of Iron. There are two types of iron from food: heme and nonheme iron. Heme iron is found in hemoglobin from animal foods, like red meats, fish, and poultry. The body absorbs more iron from heme sources compared to nonheme sources. Iron found in plant-based foods, such as lentils, beans, and dark leafy greens are examples of nonheme iron. This is the form of iron added to iron-enriched, iron-fortified foods, and supplements. Our body is not as efficient at absorbing nonheme iron, but most food sources of iron are nonheme.

Heme Iron Sources:  

  • Very good sources of heme iron contain 3.5 mg of iron or more per serving (3 ounces [oz.]) and include: beef or chicken liver, clams, mollusks, mussels, or oysters.
  • Good sources of heme iron contain 2.1 mg of iron or more per serving (3 oz.) and include: cooked beef, canned sardines (in oil), and cooked turkey.
  • Other sources of heme iron contain 0.7 mg of iron or more per serving (3 oz.) and include: chicken, halibut, haddock, perch, salmon, tuna, ham, or veal.

Nonheme Iron Sources:

  • Very good sources of nonheme iron contain 3.5 mg of iron or more per serving include: breakfast cereals enriched with iron, one cup of cooked beans, ½ cup of tofu, and 1 oz. of pumpkin, sesame, or squash seeds.
  • Good sources of nonheme iron contain 2.1 mg of iron or more per serving and include: ½ cup of canned lima beans, red kidney beans, chickpeas, or split peas, 1 cup of dried apricots, 1 medium baked potato, 1 medium stalk of broccoli, 1 cup of cooked, enriched egg noodles, and ¼ cup of wheat germ.
  • Other sources of nonheme iron contain 0.7 mg of iron or more per serving and include: 1 oz. of peanuts, pecans, walnuts, pistachios, roasted almonds, roasted cashews, or sunflower seeds, ½ cup of dried seedless raisins, peaches, or prunes, 1 cup of spinach, 1 medium green pepper, 1 cup of pasta, 1 slice of bread, pumpernickel bagel, or bran muffin, or 1 cup of rice.

Types of Iron. There are several types of iron salts when it comes to supplementation. One of the common iron salts recommended to the general public has only 20% elemental iron available. What does elemental iron mean? This means that typically the dosage listed on the label would then need to be multiplied by the percentage of elemental iron associated with that iron salt to determine how much iron is actually absorbed (the body can actually use). Please keep in mind all Celebrate® products list our dosages as the elemental dosage and you do not have to do this math (YAY!). Ferrous gluconate is even lower with only 12% available as elemental iron. Ferrous fumarate is the most recommended iron salt due to its higher bioavailability with 33% available as elemental iron. Ferrous fumarate is also gentler on the stomach (i.e., less constipating), another reason why it is the most common type of iron used in the bariatric surgery patient population.

How to Increase the Absorption of Iron. There are ways to ensure you are getting the most bang for your buck when taking iron supplements. Ensure that your iron supplement also contains vitamin C to enhance iron absorption or add vitamin C to the iron that you are taking (talk to your bariatric surgeon and/or dietitian before making any changes to your supplement regimen).

  • Do not take calcium at the same time as your iron or a multivitamin containing iron. Separate calcium and iron by at least two hours.
  • Do not take your iron product with calcium rich foods, such as with a glass of milk.
  • Do not consume a high amount of tannin-rich products (tea, wine, chocolate, coffee) throughout the day (general intake). This is especially important for those trying to increase their iron levels.
  • Avoid black tea or black coffee 1 hour before and 1 hour after taking your iron (this is especially important for those trying to increase their iron levels).
  • Consider checking your vitamin A status if you are having trouble correcting your iron levels. Sometimes once you get your vitamin A levels within normal limits, iron is better absorbed.
  • Adequate copper status is also important for normal iron metabolism.

There are also a couple drug-nutrient interactions when it comes to iron. These may not be preventable if you are told to take these medications (just something to keep in mind and further increases the need for getting iron levels checked as recommended by your bariatric surgeon). If someone takes proton pump inhibitors [PPIs] or H2 receptor antagonists, then it decreases the absorption of the iron. PPIs or H2 receptor antagonists are medications commonly used to treat heartburn or esophageal reflux (GERD). If you take thyroid medications, such as synthroid, levothyroxin, etc., then it is important to talk to your bariatric surgeon and/or pharmacist about the timing of your bariatric vitamins, as you may need to change the dosing schedule due to taking this type of medication.

Please keep in mind if your individual iron recommendations are on the upper end, talk to your bariatric program about starting at a lower dose and increasing the dosage to the recommended level to decrease the risk of toleration issues. If you have any stomach upset with taking your recommended iron, you may want to talk to your surgeon and/or dietitian about taking your iron with food to decrease stomach upset. Ensure you do not take it with calcium-rich foods.

Too Much of a Good Thing? Iron can be toxic, so do not take more or start iron without talking to your bariatric surgeon and/or dietitian and getting blood work done. The upper limit is set at 45 mg/day, but keep in mind this is for general population. There is plenty of research showing us that many bariatric patients require more than 45 mg/day to maintain their levels within normal limits. Please keep your iron supplement out of the reach of children, as it can be very dangerous to them if taken accidentally.

Iron is one of the most common deficiencies seen in the post-operative bariatric patient, but is also one of the most preventable since we have great lab parameters to evaluate an individual’s iron stores. Be sure to follow the instructions of your bariatric program in regards to iron supplementation. Be sure to get follow-up blood work completed in a timely manner. This will help you to keep your iron levels within normal limits, keep yourself feeling healthy, energized, and happy to continuing CELEBRATING your successes!