Pernicious anemia results from a deficiency of which important factor in the body?

Pernicious anemia is specifically associated with a deficiency of intrinsic factor, which is a glycoprotein secreted by the parietal cells of the stomach. Intrinsic factor is essential for the absorption of vitamin B12 (cobalamin) in the intestines. Without sufficient intrinsic factor, vitamin B12 cannot be effectively absorbed, leading to a decrease in red blood cell production and resulting in pernicious anemia.

This condition highlights the importance of intrinsic factor in the body’s ability to utilize vitamin B12, which is crucial for DNA synthesis in red blood cells. The absence or dysfunction of intrinsic factor is commonly due to autoimmune destruction of the parietal cells, which leads to gastrointestinal issues often linked to pernicious anemia.

In contrast, iron deficiency typically leads to a different type of anemia called iron-deficiency anemia, folic acid deficiencies are associated with megaloblastic anemia, and vitamin A, while important for many bodily functions, is not directly linked to the specific mechanism of pernicious anemia. Hence, the correct answer highlights the specific role that intrinsic factor plays in preventing this form of anemia.