If you live with Crohn’s disease or ulcerative colitis, you probably know about the gastrointestinal (GI) symptoms that inflammatory bowel disease (IBD) can cause.
In addition to GI symptoms, nutritional deficiencies are common in people with IBD, the three most common being iron deficiency, vitamin D deficiency, and vitamin B12 deficiency.
I’ve lived with Crohn’s disease for about 6 years now, so I understand firsthand what it is like to live with malnutrition. It can certainly be difficult to get these values into the ideal range.
It wasn’t until I studied medicine that I really understood why these deficiencies occur and what can be done about them.
The frequent toilet visits, loss of appetite, and inflammation that are common with IBD can all contribute to malnutrition and decreased nutrient absorption.
Some people with these vitamin and mineral deficiencies have no symptoms, while others may suffer from them – such as fatigue and cognitive problems – and report a decreased quality of life.
Persistent malnutrition can also lead to dangers. It is therefore important to recognize these deficiency symptoms and treat them accordingly.
The body uses iron to make a protein called hemoglobin, which enables red blood cells to carry oxygen from the lungs to the rest of the body. The upper parts of the small intestine absorb iron.
The best sources of iron are meat – especially red meat. There is also iron in plants such as leafy vegetables, but this form of iron is much more difficult for the body to absorb. Because of this, vegetarians are at higher risk of iron deficiency.
Anemia, or low hemoglobin, occurs when the body cannot make enough healthy red blood cells. Iron deficiency anemia is very common in patients with IBD, with an estimated two-thirds suffering from some form of anemia due to their illness.
It is possible to have iron deficiency without anemia.
Iron deficiency can occur in:
- Blood loss (usually GI or menstruation)
- decreased absorption (often due to inflammation in the small intestine)
- reduced iron absorption through food (vegetarian / vegan diet)
You could have chronic blood loss without even realizing it. Sometimes you can’t see the blood in your stool without a microscope.
Signs and symptoms of iron deficiency anemia include:
- shortness of breath
- Difficulty concentrating
- restless legs
- pale skin
- fast heartbeat
- Pica, a condition in which people crave for things that are not food, like ice cream or dirt
My sister always knows when I am anemic as my face has no color and my lips are particularly pale. I also notice that when I climb stairs I feel much more exhausted and don’t have the stamina or endurance to exercise the way I normally can.
Treatment involves replenishing iron stores either orally or intravenously. Some people with IBD tolerate oral iron supplements well, and others experience exacerbated gastrointestinal symptoms with oral iron, requiring the use of intravenous iron.
However, if the anemia is severe enough, a blood transfusion may be needed to return hemoglobin levels to healthy levels.
Over the years, in addition to eating many iron-rich foods, iron infusions have helped maintain my iron levels and improve anemia.
Vitamin D is a steroid hormone that our body produces through sunlight on our skin. It is also found in some foods.
Getting enough vitamin D from the sun alone can be difficult, which is why many people need a vitamin D supplement in addition to foods rich in vitamin D.
Some of the best food sources for vitamin D are:
- Cod liver oil
- Dairy products
People with IBD are at greater risk of developing vitamin D deficiency due to malnutrition and malabsorption.
Low vitamin D levels are linked to an increased risk of hospitalization and surgery in people with IBD. On the other hand, higher vitamin D levels are associated with a reduced risk of Clostridioides difficile (C. Diff) infection, for which we are also at an increased risk with IBD.
Most people who are vitamin D deficient have no symptoms.
Long-term vitamin D and calcium deficiencies increase the likelihood of developing osteoporosis or reduced bone mineral density. This increases the likelihood of fractures.
Vitamin D deficiency has also been linked to some cancers and autoimmune diseases. A deficiency is typically treated with oral vitamin D supplements.
My vitamin D levels are almost always low, so I try consistently to take vitamin D supplements and go out in the sun. This is difficult now that I am a resident doctor and no longer a lifeguard!
I can’t say I’m noticing any symptoms with this deficiency, but I do know that maintaining adequate vitamin D levels is important for both my Crohn’s disease and health in general.
About 20 percent of people with Crohn’s disease are vitamin B12 deficient.
Vitamin B12 is a vitamin that is essential for healthy red blood cell production, DNA synthesis, and healthy central nervous system function.
This vitamin occurs naturally in animal products such as meat, fish, poultry, eggs and dairy products. It is also fortified in many breads and cereals.
People on a vegan or vegetarian diet may not get enough vitamin B12 through diet alone and may need a supplement.
Vitamin B12 is absorbed in the terminal ileum, the end of the small intestine just before it joins the large intestine. This area is also the most common location for Crohn’s disease.
With active inflammation in this area, it is much more difficult to get vitamin B12 from food. If you’ve had surgery on this part of your bowel, you may also have difficulty absorbing vitamin B12.
Other causes of vitamin B12 deficiency in patients with IBD include gastritis (inflammation of the stomach) and bacterial overgrowth in the small intestine.
Vitamin B12 deficiency can be very serious and, over time, cause:
- cognitive slowdown
- Difficulty walking
- peripheral neuropathy (more in the legs than in the arms)
Treatment for vitamin B12 deficiency includes oral, sublingual, or intramuscular substitution. Intramuscular B12 injections may be required in active Crohn’s disease (terminal ileitis) or after surgery when the terminal ileum has been removed.
My vitamin B12 levels are on the low end, but I can’t say I have any symptoms from it. I know my terminal ileum is affected by my Crohn’s disease, so I take oral vitamin B12 supplements to help maintain my levels as I am not getting enough from food alone.
Nutritional deficiencies are extremely common in patients with Crohn’s disease and ulcerative colitis. These deficiencies can lead to unpleasant symptoms, impair the quality of life and, if left untreated, even lead to potentially dangerous complications.
Personally, I feel most comfortable when my vitamin levels – especially iron – are in a healthy range.
Be sure to speak to a doctor about your particular chances of developing nutritional deficiencies and make sure they are treated appropriately.
Jamie Horrigan, MD is a passionate Crohn’s disease advocate who truly believes in the power of diet and lifestyle. When she’s not looking after patients in the hospital, you can find her in the kitchen. For some great gluten free, paleo, AIP, and SCD recipes, lifestyle tips, and to keep up with your journey, follow her blog, Instagram, Pinterest, Facebook, and Twitter.