Initial treatment for pernicious anemia?

Initial treatment for pernicious anemia?

• A. Oral B12 alone
• B. Intravenous fluids
• C. Corticosteroids
• D. Intramuscular B12 replacement

Answer: (D)

Pernicious anemia happens when autoimmune destruction of gastric parietal cells leads to lack of intrinsic factor, so vitamin B12 can’t be absorbed properly. The quickest and most reliable way to fix the deficiency is to give vitamin B12 by injection into the muscle, bypassing the need for intrinsic factor. This rapidly elevates B12 levels and reverses the hematologic effects, and it’s the standard initial treatment. Oral B12 alone isn’t reliable initially because absorption depends on intrinsic factor; although some very high oral doses can be absorbed passively, that’s not the standard first-line approach. Intravenous fluids don’t treat the underlying B12 deficiency, and corticosteroids don’t provide the B12 needed to correct the deficiency. Lifelong B12 replacement—often monthly injections after an initial intensive phase—is typically required.

Pernicious anemia happens when autoimmune destruction of gastric parietal cells leads to lack of intrinsic factor, so vitamin B12 can’t be absorbed properly. The quickest and most reliable way to fix the deficiency is to give vitamin B12 by injection into the muscle, bypassing the need for intrinsic factor. This rapidly elevates B12 levels and reverses the hematologic effects, and it’s the standard initial treatment.

Oral B12 alone isn’t reliable initially because absorption depends on intrinsic factor; although some very high oral doses can be absorbed passively, that’s not the standard first-line approach. Intravenous fluids don’t treat the underlying B12 deficiency, and corticosteroids don’t provide the B12 needed to correct the deficiency. Lifelong B12 replacement—often monthly injections after an initial intensive phase—is typically required.