Use Your Knowledge of the Treatments and Interactions Associated with Deficiency

Use your knowledge of the treatments and interactions associated with deficiency anemias to explain to a patient why she should not take cimetidine within 2 hours of her cobalamin treatment.

A) Cimetidine decreases gastric acid so that vitamin B₁₂ cannot combine with available intrinsic factor, impairing but not totally inhibiting the absorption of vitamin B₁₂.
B) Cimetidine decreases gastric acid so that vitamin B₁₂ cannot combine with available intrinsic factor, totally inhibiting the absorption of vitamin B₁₂.
C) Cimetidine decreases intrinsic factor production so that vitamin B₁₂ cannot be absorbed.
D) None of these are correct.