DEAR DR. BLONZ: Could you please tell me about Crohn's disease and how vitamin B-12 might be involved? I have needed occasional shots of B-12 before, and now my close friend has been diagnosed with Crohn's disease and will need regular B-12 shots. What are these shots for? Supposedly, they give energy, but I want to know more. -- G.C., San Jose, Calif.
DEAR G.C.: Crohn's disease involves a chronic inflammation of the intestines and it exists in varying levels of severity. Researchers have yet to unravel the cause, and, unfortunately, there is no cure at the present time. However, new medications and therapies are helping provide some relief. The National Library of Medicine has an information page (tinyurl.com/4f5xgw4), and there is more available from the Crohn's and Colitis Foundation of America (ccfa.org).
Vitamin B-12 is essential for the creation of cells, and is present almost exclusively in foods of animal origin. It's prevalent in most meats (especially organ meats), dairy products (especially yogurt) and eggs, and can be added to certain vegetarian foods.
It takes two separate components for vitamin B-12 to be absorbed into the body. The first component is the vitamin itself, ingested from foods or supplements. The second is a protein manufactured by the body, referred to as the "intrinsic factor." This factor bonds with the vitamin and serves as an essential escort to allow passage through the absorptive surface of the intestines. Without its intrinsic factor, little if any dietary vitamin B-12 gets into your system.
People who have ailments or injuries that affect the absorptive surface of the digestive tract are often unable to properly digest and absorb vitamin B-12 or other nutrients. Crohn's disease is an example of this. There are also certain medications that affect vitamin B-12 absorption, and deficiencies can also develop if the body is unable to produce a sufficient amount of the intrinsic factor. Finally, a B-12 problem can develop in the elderly when there is insufficient production of digestive stomach acid. This condition effectively decreases the amount of vitamin B-12 available for absorption, and affects an estimated 10 to 30 percent of the elderly.
One solution in such cases, especially if the absorptive surface is malfunctioning, is to give the B-12 via injection. That way, the vitamin goes directly into circulation, bypassing any need for the intrinsic factor, digestion or absorption.
As stated above, vitamin B-12 is essential for the creation of cells. The cells with the most rapid turnover, i.e., the shortest lifespan, are red blood cells. This explains why one of the first symptoms of a vitamin B-12 deficiency is a reduction in the number of red blood cells, otherwise known as anemia -- in this case, a "pernicious anemia." Red blood cells carry oxygen from the lungs to the working cells, then carry carbon dioxide from the working cells back to the lungs to be eliminated from the body. It makes sense, then, that certain types of anemia are associated with fatigue and weakness. It also makes sense that giving B-12 to a deficient body can help spark energy. If there is no vitamin B-12 deficiency to begin with, however, these shots would not be expected to do much.
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