Crohn’s disease may cause a deficiency of essential nutrients due to malabsorption, limited diet, and symptoms such as diarrhea. A person with Crohn’s disease may lack essential nutrients, including iron, calcium, and vitamin D.
According to the Crohn’s & Colitis Foundation (CCF), malnutrition is common in inflammatory bowel disease (IBD), especially in Crohn’s disease, with studies indicating that it affects 20–85% of people with IBD.
The CCF also notes that approximately 60% of people with IBD feel that nutrition plays an important role in managing their condition. However, few discuss diet with a doctor.
This article explains which vitamins, minerals, and other nutrients a person with Crohn’s disease may lack. It also outlines the signs and symptoms related to deficiencies in these nutrients.
Crohn’s disease causes inflammation in the gastrointestinal (GI) tract, commonly affecting the small intestine and the beginning of the large intestine.
However, inflammation can be present in any part of the GI tract and through the entire thickness of the intestinal wall.
Inflammation can cause difficulty digesting and absorbing nutrients. Doctors refer to this as malabsorption.
Malabsorption can lead to deficiencies in essential vitamins, minerals, and other nutrients, resulting in further health complications.
Additionally, some symptoms of Crohn’s disease can lead to malnutrition:
- Severe diarrhea: This can result in dehydration and weight loss. It can also cause a depletion of fluids, nutrients, and electrolytes, such as sodium, magnesium, potassium, zinc, and phosphorus.
- Rectal bleeding: This can occur due to ulcers in the intestines. It can lead to iron deficiency and anemia.
- Abdominal pain and nausea: This can reduce a person’s appetite. As a result, they may not eat enough and not consume the amount of nutrients they need.
- Frequent bowel movements: A person may eat less to avoid diarrhea. Not eating enough can in turn lead to malnutrition.
Can a person’s diet lead to Crohn’s disease?
The CCF notes that although a person’s diet can aggravate Crohn’s disease, it does not cause the condition.
Crohn’s disease can occur due to genetic and environmental factors.
General signs of malnutrition include:
- weight loss
- weakness
- loss of muscle mass
- undereating
- severe restriction of food types and variety
People with Crohn’s disease can experience weight loss. A 2014 study reports that
Weight loss can also continue throughout the disease. Another study indicates that this affects
People with Crohn’s disease may have difficulty consuming enough calories or macronutrients from food. Macronutrients include protein, fats, and carbohydrates.
This can be the result of diarrhea and eating less food in an effort to avoid aggravating symptoms.
When a person does not consume enough calories, protein, and other essential nutrients, protein-energy malnutrition can occur.
Protein-energy malnutrition causes changes in body composition. For example, people with Crohn’s disease
A person with Crohn’s disease may develop a deficiency in the
Iron
Rectal bleeding that results from stomach ulcers and insufficient iron consumption can lead to iron deficiency.
Signs that a person may have iron deficiency
- GI upset
- weakness
- fatigue
- lack of concentration
- difficulty remembering things
- being more prone to infections
- cold intolerance
Doctors can diagnose iron deficiency with a simple blood test.
Calcium
According to a
People with Crohn’s disease may also have low levels of vitamin D, which
Calcium deficiency can lead to osteoporosis, or decreased bone density.
The
Vitamin D
People with Crohn’s disease may have vitamin D deficiency due to malabsorption and inadequate intake.
Vitamin D is
Signs of severe vitamin D deficiency include bone pain and muscle weakness.
Zinc
A person with Crohn’s disease
Symptoms of zinc deficiency
- hair loss
- eye and skin sores
- loss of appetite
- diarrhea
- weight loss
- problems with wound healing
- inability to taste food
- low levels of alertness
Magnesium
Malabsorption and chronic diarrhea can result in a magnesium deficiency in those with Crohn’s disease. Magnesium helps regulate nerve and muscle function, blood pressure, and blood sugar levels.
Signs of magnesium deficiency are not immediately obvious. However, symptoms
- loss of appetite
- nausea
- vomiting
- weakness
- fatigue
A severe deficiency can cause:
- numbness
- muscle cramps
- tingling
- seizures
- changes in personality
- abnormal heart rhythm
B vitamins
There are eight B vitamins that help the body make energy from the food a person eats and form red blood cells.
A deficiency in B vitamins
Signs of vitamin B deficiency vary depending on which vitamin B is insufficient in a person’s body.
Learn more about the symptoms of vitamin B deficiency here.
Vitamin A
A person may experience vitamin A deficiency due to malabsorption and low intake.
Vitamin A is an important antioxidant nutrient for the immune system and supports the cells in the gut lining.
Poor wound healing and night blindness can be symptoms of vitamin A deficiency.
Vitamin K
A deficiency in vitamin K may arise due to malabsorption, a limited diet, or the use of antibiotics.
Vitamin K is a nutrient that is important for bone health, blood clotting, and other bodily functions.
If a person develops severe vitamin K deficiency, they can experience problems with bleeding and bruising. It can also reduce bone strength.
Severe diarrhea can cause dehydration and depletion of electrolytes, such as sodium and potassium.
Sodium plays a role in the functioning of muscles and nerves. It also helps maintain the balance of fluids in the body.
Potassium helps nerve and muscle function as well. It also supports regular heartbeat.
If a person’s potassium level is too low, they
- constipation
- tiredness
- muscle weakness
- increased urination
- high blood sugar levels
- irregular heartbeat
Therefore, if a person has chronic or severe diarrhea, they should consult a doctor, who may prescribe medications or supplements to address electrolyte imbalances.
The CCF recommends people ask a doctor for tests for nutrient deficiencies even if they are not showing any symptoms of malnutrition.
Furthermore, people should avoid foods that worsen their symptoms, and work with a doctor to identify a list of nutritious foods they can eat.
Certain foods may be easier for people with Crohn’s disease to digest. These include:
- low fiber fruits, such as bananas, cantaloupe, and cooked fruits
- lean protein, such as fish, white meat, eggs, and tofu
- refined grains, such as white pasta, oatmeal, and gluten-free bread
- fully cooked, seedless, and skinless non-cruciferous vegetables
- protein shakes
A doctor may advise a person to avoid certain foods when they are experiencing a flare or if they have a stricture, which is a narrowing of the intestine due to inflammation or surgery.
People should work with a doctor to clarify what foods are right for them according to their symptoms and whether they are experiencing a flare.
Learn more:
Vitamin and mineral supplements can help prevent a deficiency and avoid further health issues.
A doctor or dietitian can advise a person with Crohn’s disease about what supplements to take.
Some supplements can cause GI symptoms, and people should check the ingredients for sugar alcohols, lactose, and artificial coloring. Furthermore, it may be best to avoid taking supplements on an empty stomach.
Supplements are available as tablets, liquid supplements, and oral nutrition products. A healthcare professional can advise a person which one is most suitable for them.
Further resources
For more in-depth resources about vitamins, minerals, and supplements, visit our dedicated hub.
People with Crohn’s disease are likely to experience malnutrition and weight loss. They can also develop deficiencies in essential vitamins, minerals, and macronutrients, leading to further health issues.
It is advisable for people with Crohn’s disease to work with a healthcare professional to identify which foods they can eat for adequate nutrition.
Doctors or dietitians can also help determine whether a person with the condition needs supplements and which are best for the person’s needs.
People with Crohn’s disease should get tests for nutritional deficiencies regularly, even if they are not presenting with any symptoms.