Disclaimer: This article was written after attending AIBD 2021; all information is presented as an attendee to the conference, not as a presenter.
If you have inflammatory bowel disease, you’ve probably heard your doctor talk about iron at one point in time. Maybe you had to take iron supplements, or get an iron infusion because your levels were too low. Iron is a key nutrient for keeping our bodies healthy and running smoothly. Iron plays a role in physical growth, neurological development, cellular functioning, hormone synthesis, and most importantly transfer of oxygen to our muscles and cells. So if we are deficient in iron, can’t we just take a supplement? Not so fast. If that were true, there would be no need for an entire symposium on iron. There are a lot of different factors for your doctor to consider when looking for an iron deficiency and determining what treatment to use to correct it. In this article, I will take you through the wonderful presentation from AIBD 2021 covering these factors by Dr. Gary Lichtenstein, Dr. Stephen Hanaeur, and Dr. Millie Long.
One of the first topics, covered by Dr. Long, concerned iron absorption. Iron in the diet comes in two forms: Heme iron and Nonheme iron. Heme iron is found in meat, and is more readily absorbed. Nonheme iron comes from plant sources such as nuts, beans, vegetables, and fortified grains and is less readily absorbed. Dr. Long made the point that overall, we only absorb about 10% of the iron we actually eat. The average American diet includes about 7mg of iron from a mixture of heme and non-heme sources for every 1000 calories consumed. On a 2000 calorie diet, that would be about 14mg of iron per day. For reference, the recommended dietary allowance (RDA) for iron in males is 8mg per day, and in females is 18mg per day. We can see that most people get enough iron from diet alone, so why do people with IBD end up becoming deficient?
Iron deficiency is almost always due to blood loss, but can also be caused by a lowered ability to absorb iron (malabsorption) or not getting enough from diet. Unfortunately, one of the factors that can cause us to malabsorb iron is inflammation. Inflammation and blood loss are both relatively common in IBD, which leads to a scenario where we can easily become deficient in iron. If we are deficient in iron for a long period of time, we can develop anemia. Remember how earlier I said one of the most important roles of iron is in transporting oxygen through the blood? Anemia occurs in iron deficiency when our red blood cells shrink in size and aren’t able to carry oxygen as well to the rest of our body.
Iron deficiency can present in a lot of different ways. Some of the most common ways may be hair loss, cold intolerance, fatigue, and excessive consumption of substances with little to no nutritional value such as ice or cornstarch (often referred to as PICA).
So, how is iron deficiency treated? Dr. Hanaeur presented on the two main options: oral or intravenous (IV) iron. Oral iron refers to an iron supplement in a pill form that you would take by mouth, while IV refers to infusing iron directly into the bloodstream through a vein. While oral iron can be convenient and cost effective, it may not be the best choice in active IBD because like we discussed before inflammation lowers absorption. Oral iron may also cause GI side effects such as nausea, flatulence, and diarrhea. I think many of us with IBD would agree that more GI upset is the last thing we need.
IV iron on the other hand, achieves a faster response and is better tolerated than oral iron. IV iron can also have some adverse side effects, but they are less frequent than with oral iron and often do not involve the GI tract. Dr. Hanaeur also notes that IV iron doesn’t have the same issue of a low absorption that oral iron does. All of the iron administered through IV is available to be used by the body. This feature makes it a good choice during inflammation and when there is a large deficiency of iron.
Iron deficiency is common in IBD, and can contribute significantly to quality of life. It is important for both patients and providers to monitor for this deficiency and work together to correct it if found.