What is a characteristic of macrocytic anemia?

Macrocytic anemia is primarily characterized by an increased mean corpuscular volume (MCV), indicating that the red blood cells produced are larger than normal. This condition often arises due to deficiencies in essential nutrients necessary for red blood cell production, such as vitamin B12 or folate. The high MCV is a key diagnostic marker used by healthcare providers to distinguish macrocytic anemia from other forms, such as microcytic anemia, where red blood cells are smaller than normal, indicated by a low MCV.

In the context of the other options, total hemoglobin levels in macrocytic anemia can vary; they are not typically normal, especially if the anemia is significant. Additionally, iron deficiency is more commonly associated with microcytic anemia, which is characterized by small red blood cells and low MCV. Understanding these relationships helps clarify why a high MCV is considered a defining characteristic of macrocytic anemia.