Crohn’s Disease and Vitamin B12: The Lowdown
For patients with Crohn’s disease, one discussion topic that’s standard is vitamin B12. Many gastroenterologists’ offices have displays of literature in the waiting room that discuss this vitamin.
So what’s the deal? Why is it important to a Crohn’s patient?
One of the functions of vitamin B12 is maintaining the body’s metabolism. It creates red blood cells and plays a crucial role in how the central nervous system functions. Many people have heard a B12 deficiency linked to anemia. B12 is also the only B vitamin that’s stored in the body. Among the foods with high levels of this vitamin are meat, shellfish, milk and other dairy products, eggs and poultry.
So if a Crohn’s patient has a B12 deficiency, it can be corrected by swallowing a supplement, right?
It’s not that simple. It depends on where in the gut the disease occurs, severity of the illness and how much small intestine the patient has.
Vitamin B12 gets absorbed by the terminal ileum, which is the end of the small intestine. This is a very common site of Crohn’s disease. It’s possible that disease in that portion of the bowel has made it impossible for a patient to absorb enough B12 from food or supplements to meet crucial needs. Doctors use a blood test to check the level of B12 present.
One of the most common reasons for B12 deficiency in Crohn’s patients is surgical removal of the terminal ileum. Some patients develop a disorder known as short bowel syndrome as the result of extensive small bowel surgery for any of a number of conditions.
Almost all digestion of nutrients occurs in the small intestine, which is about 23 feet long in an adult. As many as 20,000 people in the United States suffer from short bowel syndrome, many of them Crohn’s patients. One of the potential consequences of this disorder is a vitamin B12 deficiency.
Since a deficiency can cause damage to the brain and spinal cord, doctors routinely prescribe the vitamin when surgery has removed at least 1.5 feet of the ileum, the bottom of three sections of the small intestine.
When the portion of the bowel that absorbs B12 has been removed or is too diseased to process enough of the vitamin, the patient needs supplementation other than by oral means. That typically means monthly B12 injections or a weekly nasal spray. A patch is also now on the market.
For many years after my first small bowel resection, I trudged every month to the gastroenterologist’s office for a B12 injection. I could tell from the slowly accumulating symptoms each month that I had a deficiency. I bumped into walls when walking a straight path, and I inverted words. “Bookkeeping” became “kookbeeping.” Twice a year, the doctor ordered blood tests to make sure my B12 level remained within normal range after the injections.
About 10 years ago, I changed internists. The first thing the new doctor asked me was why I was still getting “those shots” instead of using a weekly nasal spray. If he had had a sample in the office, I probably would have ripped it out of his hands.
This meant no more time off work each month. No more arguing with the insurance company about paying for vitamin injections. No more accumulating symptoms as the month came to an end.
This has been a very good move. I use the spray every Wednesday morning and order 90 days’ worth at a time from my mail-order pharmacy. After checking my B12 levels three months in a row, the internist now orders levels twice a year, and they’re always within normal range.
A friend of mine, also a Crohn’s patient, can’t bring herself to switch from injections to spray. For her, it’s an issue of facing change.