Vitamin B-12 Replacement Therapy for Ileostomates

by Bob Baumel, Ostomy Association of North Central Oklahoma, UOAA update 7/2012

Vitamin B-12 is, under normal conditions, absorbed in only a small section of the terminal small intestine (ileum), raising the possibility of B-12 deficiency if that section of the ileum has been removed surgically or damaged by disease.  People who may have lost that portion of ileum include some ileostomates, people who had a J-pouch or Kock pouch, and some people with urinary diversions (especially continent urinary diversions) made using the terminal ileum.  A condition such as Crohn's disease may have damaged the terminal ileum, even if it hasn't been removed surgically.

Vitamin B-12 is necessary for many metabolic processes including development of red blood cells, and also maintains normal functioning of the nervous system.  Deficiency causes anemia (reduced oxygen-carrying capacity of the blood resulting in fatigue) and can also cause nervous system damage.  It's worth noting that folic acid (another B vitamin) can correct the anemia caused by vitamin B-12 deficiency, but it will not correct the nerve damage caused by B-12 deficiency.  So it's important to get enough vitamin B-12. 

If you think you are at risk for vitamin B-12 deficiency, you can ask your doctor to check your serum (blood) B-12 level.  This test can be added easily to routine blood testing.  If your ability to absorb vitamin B-12 by the normal pathway involving the terminal ileum has been impaired, you can supplement the vitamin by three basic methods.

By Injection:  This method bypasses the normal gastrointestinal process of B-12 absorption by inserting it into the body by intramuscular or subcutaneous injection.  B-12 injections may be self-administered in the same way that diabetic patients can give themselves insulin shots.  Maintenance therapy may require only one B-12 injection per month.

Nasally:  This method bypasses the normal gastrointestinal absorption process, as vitamin B-12 can be absorbed through nasal mucous membranes.  The nasal form of B-12 was developed first as a nasally applied gel and later a true nasal spray (brand name Nascobal).  This product is marketed by the company Strativa Pharmaceuticals, who promotes it as the only FDA-approved form of vitamin B-12 besides the injectable form.  Nasal B-12 can be effective, but because one company has sole rights to distribute it in the U.S., it can be an expensive way to get your vitamin B-12.

Orally:  Until recently, doctors believed that B-12 taken orally was useless to people who lack the normal absorption mechanism involving the terminal ileum.  That opinion has changed, however, as research has revealed that even in such people, when a large dose of vitamin B-12 is taken orally, a small fraction (typically 1%) gets absorbed by mass-action transport across the gut. 

Note:  Time Released medications should, in general, be avoided if you have an ileostomy, as they may pass through your gut.