A dietary deficiency of which of the following causes a macrocytic anemia resembling pernicious anemia?

A dietary deficiency of folacin, or folic acid, can lead to macrocytic anemia, a condition where red blood cells are larger than normal. This type of anemia resembles pernicious anemia, which is often associated with vitamin B12 deficiency. Both conditions involve a problem with the body's ability to produce healthy red blood cells due to inadequate synthesis of DNA, which is critical for cell division.

Folic acid plays an essential role in the formation of red blood cells and the synthesis of nucleic acids (DNA and RNA). When there is a deficiency of folic acid, the body cannot produce normal red blood cells efficiently, resulting in macrocytic anemia. This anemia is characterized by an increased mean corpuscular volume (MCV) because the red blood cells are larger than typical size.

While vitamin B12 is also crucial for red blood cell production and deficiency can lead to a similar macrocytic anemia, the question specifically asks about a dietary deficiency causing this type of anemia, and in this context, folic acid deficiency is a common cause, particularly in populations with low dietary intake.

Iron deficiency, on the other hand, typically leads to microcytic anemia, wherein red blood cells are smaller. Vitamin C does not directly relate to the production