Micronutrient Deficiencies and Crohn’s Disease

Medically Reviewed by Sabrina Felson, MD on June 29, 2022
4 min read

Crohn’s disease is a chronic disorder that can affect all parts of your digestive tract, most often your small intestine and sometimes your large intestine.

With Crohn’s, your body may have a hard time getting all the nutrients it needs. More than half of people with this and other types of inflammatory bowel disease (IBD) don’t get the right amount of essential vitamins and minerals, known as micronutrients.

Dietary minerals, such as calcium, phosphate, potassium, magnesium, iron, and trace elements, like zinc, selenium, and copper, are important for maintaining the cells in your body and to ensure the proper function of enzymes. Enzymes are an essential part of the digestive process, breaking down fats, proteins, and carbohydrates. Because your diet plays an important role in Crohn’s disease, talk to your doctor about any foods that give you discomfort.

Anemia is one of the most common complications of Crohn’s, affecting about 70% of people with the disease. A lack of iron is the most common cause of anemia. You may have symptoms like fatigue, sleepiness, anorexia, and nausea.

Iron is important for the hemoglobin in your red blood cells, which helps deliver oxygen throughout your body. Your doctor should check your iron levels regularly.

The best way to get the iron you need is by eating a balanced diet. A diet rich in iron includes these foods:

  • Iron-fortified cereals
  • Oysters and sardines
  • White beans, lentils, kidney beans, and chickpeas
  • Spinach
  • Beef and beef liver
  • Canned and stewed tomatoes
  • Tofu

When you are eating foods rich in iron, try to take them with foods that have vitamin C, which can help your body absorb iron more efficiently. Vitamin C-rich foods include fruits and vegetables like bell peppers, broccoli, berries, citrus fruits, and tomatoes.

Your body may also be lacking in several other important micronutrients, so watch for these symptoms:

  • Calcium: low blood pressure, heart rhythm disorders, muscle cramps and tingling
  • Vitamin B12: confusion and memory loss, cardiovascular disease, bone fractures
  • Vitamin D: too little calcium in your blood, weak and brittle bones
  • Folate: anemia, diarrhea, sore tongue, weight loss, nervous instability
  • Magnesium: cramps, spasms, seizures
  • Vitamin B6: scaly patches on the scalp, confusion, depression
  • Zinc: inadequate growth, itchy red or purple blisters, impaired night vision, anorexia
  • Vitamin B1 and biotin: fatigue

Deficiencies are more common when your disease is active than when you are in remission. A lack of vitamin D and vitamin K are likely when you are in a heightened inflammatory state.

There are several reasons your body might not be getting enough of these micronutrients.

Chronic pain and swelling in your intestines can interfere with nutrient absorption. Most people with Crohn’s disease have weight loss and malnutrition at some point. This may be the result of:

  • Active bowel inflammation (can cause difficulty digesting)
  • Lack of appetite (may result from abdominal pain and nausea)
  • Medical or surgical treatments

You may have more chances of micronutrient deficiency if you have had bowel resection surgery. That's when your doctor removes a diseased section of your bowel and connects the two healthy ends together. That means though, there is less intestine available to absorb nutrients. Younger people may be more likely to show deficiencies after this surgery.

You may also have diarrhea-related gastrointestinal loss, or poor intake of nutrients caused by disease-related anorexia.

A lack of proper nutrients can complicate the progress of your disease treatment. Your care team should check you regularly for any signs of vitamin and mineral deficiencies to improve your quality of life.

Some common medicines you take to treat Crohn’s disease can interfere with nutrient absorption. These include corticosteroids, methotrexate, and sulfasalazine.

Because your body may not be absorbing properly, your doctor may prescribe a multivitamin with minerals. Sometimes chewable or liquid forms of these supplements are easier for your body to process. Calcium and vitamin D are especially important if you are taking a high dose of steroids or if you have been taking them for a long time.

And as with any over-the-counter medications, read the labels on supplements carefully. There may be starch or lactose additives, artificial colors, or sugars that can aggravate your symptoms.

Some supplements can also cause nausea and diarrhea, and most should not be taken on an empty stomach.

Crohn’s can be a complicated condition that can affect all parts of your digestive tract, from your throat to your anus. Because of that complexity, doctors are not completely sure whether Crohn’s is the cause or the result of a deficiency in nutrients.