A 42-year-old male has fatigue, pale skin, and shortness of breath with exercise. Blood test shows a macrocytic, hyperchromic anemia with hyper-segmented neutrophils and normal folate levels. The patient has been taking omeprazole for over 3 years to treat gastric reflux disease. One method to treat this patient is to do which one of the following?

The patient is displaying megaloblastic anemia caused by a deficiency of vitamin B12 . The use of omeprazole to reduce acid production in the stomach also reduces the ability of B12 , bound to ingested proteins, to be released by the proteins to be bound by intrinsic factor for effective absorption into the blood. Providing injections of B12 will bypass the need for separation of B12 from its binding proteins and will allow B12 to circulate throughout the body and reach its intracellular targets and proteins. Oral B12 would also work under these conditions. The patient is unlikely to have an intrinsic factor problem (owing to his age), and intrinsic factor cannot be given orally or via injection (because it needs to work in the intestine). For lack of intrinsic factor, injections of B12 are also required. The patient has normal folate levels, so giving more folate will not help the anemia, and vitamin B6 is not involved in these reactions.