Pernicious anemia can be fatal unless vitamin B12 replacement is given; lifelong replacement is required.

• A. Iron supplementation
• B. Vitamin B12 replacement
• C. Folic acid
• D. Vitamin C

Answer: (B)

Pernicious anemia is a B12 deficiency caused by autoimmune loss of intrinsic factor, which is needed to absorb vitamin B12 in the gut. Without B12, the bone marrow cannot make normal red blood cells, causing macrocytic, megaloblastic anemia, and B12 is also essential for nerve myelin; deficiency can lead to serious neurological damage. Because the underlying factor deficiency is permanent, lifelong B12 replacement is required to prevent progression and potential fatal outcomes. Replacing iron wouldn’t fix this condition since the issue isn’t iron; folic acid can improve the blood count but won’t prevent neurological problems and can mask B12 deficiency; vitamin C has no role in treating pernicious anemia.