A person with Crohn’s disease will experience abdominal pain and unintentional weight loss. They may also have difficulty absorbing certain foods, resulting in nutrient deficiencies. One that commonly occurs is a vitamin B12 deficiency.
Crohn’s disease, a form of inflammatory bowel disease (IBD), is a lifelong condition that results in inflammation and irritation of the digestive tract. Crohn’s disease commonly affects the small intestine and the initial part of the large intestine, which is responsible for absorbing nutrients such as vitamin B12.
Vitamin B12 is naturally present in certain foods and is also available as a dietary supplement. It plays an important role in various bodily functions, including developing the central nervous system, red blood cell formation, and DNA synthesis.
This article explains why a person with Crohn’s disease may have a vitamin B12 deficiency and how doctors may diagnose it. It also looks at recognizing, preventing, and reversing a vitamin B12 deficiency.
Vitamin B12 deficiency is
Some people with Crohn’s disease may undergo surgical removal of part or all of the ileum, making it difficult to absorb vitamin B12.
Warning signs of deficiency
A person with vitamin B12 deficiency may present with symptoms
- fatigue
- diarrhea
- headaches
- glossitis, which is a swollen and inflamed tongue
- jaundice
- low mood
- lack of energy
- weight loss
- numbness and tingling in the hands and feet
- changes in skin tone, such as pallor in people with light skin and an ashen complexion in those with dark skin
A person with vitamin B12 deficiency may also experience various neurological symptoms, including:
- loss of deep tendon reflexes
- difficulty with concentration
- memory loss
- irritability
- problems with balance and walking
If someone experiences any of the above symptoms, they need to consult a doctor. The doctor can rule out other possible causes of the symptoms.
Learn more about Crohn’s disease.
The doctor usually begins the diagnostic process by asking about a person’s symptoms and medical history and then performing a physical exam.
They might also conduct a neurological exam if the person is experiencing difficulty concentrating or has any tingling or numbness in their hands or feet.
Blood tests
Healthcare professionals will order laboratory tests to confirm a diagnosis.
Initial blood tests may include a complete blood count (CBC) to measure for anemia.
A vitamin B12 level of less than
If a person’s vitamin B12 level remains unclear, a doctor may order additional tests, such as a methylmalonic acid (MMA) blood test. This test measures the blood level of MMA, which the body produces during metabolism. Vitamin B12 has a role in metabolism. Therefore, if the body is deficient in vitamin B12, the level of MMA is likely to increase.
Another type of test is the homocysteine test, which measures the level of an amino acid called homocysteine in the blood. Vitamin B12 breaks down homocysteine to produce components that the body uses. A vitamin B12 deficiency will likely result in a higher homocysteine level in the blood.
A person can take steps to prevent or even reverse a vitamin B12 deficiency.
Supplements
According to the
Vitamin B12 is available in supplements in different doses. These supplements contain either vitamin B12 alone or a combination of B-complex vitamins.
Supplements that contain only vitamin B12 tend to contain doses ranging from 500 to 1,000 mcg. In contrast, supplements that contain multiple B-complex vitamins provide 50 to 500 mcg of vitamin B12.
These supplements do not typically require a prescription, and people can buy them over the counter in supermarkets or pharmacies. Vitamin B12 is also available in tablets and lozenges that people place under the tongue. However, a person needs to speak with a doctor before taking it to ensure the right dosage.
Injection
A person with a severe vitamin B12 deficiency or difficulty absorbing vitamin B12 may require an injection of vitamin B12, which some people refer to as a B12 shot. The injection, which doctors deliver into the muscle, typically contains vitamin B12 as cyanocobalamin or hydroxocobalamin.
In a 2019 study, participants with Crohn’s disease reported improvements in their symptoms shortly after receiving a vitamin B12 injection.
How to include vitamin B12 in the diet
A person can also increase their vitamin B12 intake by following a diet rich in vitamin B12. Foods that are high in vitamin B12
- beef liver
- seafood, such as:
- fortified breakfast cereals
- beef
- dairy, such as:
- vegetables, such as:
- lettuce
- asparagus
- spinach
- dark leafy greens
Learn more about foods that can increase and reduce vitamin B12 levels.
Other possible causes of a vitamin B12 deficiency
- pernicious anemia
- prolonged use of certain medications, such as metformin
- following a strict vegan or vegetarian diet
- certain infections, such as with the tapeworm Diphyllobothrium latum
- celiac disease
- older age
- high intake of alcohol
Other nutritional supplements may also benefit someone with Crohn’s disease. These may help ensure that a person gets the correct amount of vitamins and nutrients, especially if they are not absorbing enough from food alone.
Some supplements that a person may benefit from include:
Below are answers to common questions about a B12 deficiency.
Can Crohn’s disease cause B12 deficiency?
Crohn’s disease typically affects the ileum, the last portion of the small intestine, which absorbs vitamin B12. This, in turn, can result in B12 deficiency.
What is the most common vitamin deficiency in Crohn’s disease?
Common deficiencies in inflammatory bowel diseases include calcium, B12, vitamin D, folate, and iron.
How much B12 should a person with Crohn’s disease take?
A high dose of
What autoimmune disease can cause low B12?
Pernicious anemia is a
Crohn’s disease is a chronic condition that results in digestive tract inflammation. A person with Crohn’s disease may have trouble absorbing certain vitamins, such as vitamin B12, if they have undergone the removal of part or all of the ileum or if the disease affects their ileum.
Other causes of a vitamin B12 deficiency include certain medications, a vegan or vegetarian diet, and certain infections.
A doctor usually diagnoses a vitamin B12 deficiency according to a physical examination and blood tests. The doctor may advise the person to take supplements, receive vitamin B12 injections, or eat more foods rich in vitamin B12, such as seafood, vegetables, and meat.