What type of anemia is primarily caused by B12 and folate deficiency?

What type of anemia is primarily caused by B12 and folate deficiency?

• A. Microcytic anemia
• B. Normocytic anemia
• C. Macrocitic anemia
• D. Sideroblastic anemia

Answer: (C)

Macrocitic anemia, also known as megaloblastic anemia, is primarily caused by deficiencies in vitamin B12 and folate. This condition is characterized by the production of larger-than-normal red blood cells (macrocytes) due to impaired DNA synthesis. Both B12 and folate are crucial for DNA replication and cell division, particularly in the rapid production of red blood cells in the bone marrow. When these nutrients are deficient, the maturation process of red blood cells is disrupted, leading to the characteristic enlargement observed in macrocytic anemia. In contrast, microcytic anemia is typically associated with iron deficiency and leads to smaller-than-normal red blood cells. Normocytic anemia features red blood cells that are normal in size but are reduced in number, which can be due to various causes such as chronic disease or acute blood loss. Sideroblastic anemia is characterized by the presence of abnormal red cell precursors in the bone marrow that cannot properly incorporate iron into hemoglobin, resulting in ineffective erythropoiesis. Therefore, the definition of macrocitic anemia directly corresponds to the conditions caused by B12 and folate deficiencies, making it the correct choice.

Macrocitic anemia, also known as megaloblastic anemia, is primarily caused by deficiencies in vitamin B12 and folate. This condition is characterized by the production of larger-than-normal red blood cells (macrocytes) due to impaired DNA synthesis. Both B12 and folate are crucial for DNA replication and cell division, particularly in the rapid production of red blood cells in the bone marrow. When these nutrients are deficient, the maturation process of red blood cells is disrupted, leading to the characteristic enlargement observed in macrocytic anemia.

In contrast, microcytic anemia is typically associated with iron deficiency and leads to smaller-than-normal red blood cells. Normocytic anemia features red blood cells that are normal in size but are reduced in number, which can be due to various causes such as chronic disease or acute blood loss. Sideroblastic anemia is characterized by the presence of abnormal red cell precursors in the bone marrow that cannot properly incorporate iron into hemoglobin, resulting in ineffective erythropoiesis. Therefore, the definition of macrocitic anemia directly corresponds to the conditions caused by B12 and folate deficiencies, making it the correct choice.