Which deficiency leads to macrocytic anemia?

Macrocytic anemia is characterized by the presence of larger than normal red blood cells, which is primarily caused by deficiencies in certain nutrients essential for red blood cell production. Both vitamin B12 and folate are crucial for DNA synthesis and cell division. When there is a deficiency in either of these vitamins, it disrupts the normal maturation process of red blood cells, resulting in the formation of larger immature cells, hence leading to macrocytic anemia.

Vitamin B12 is vital for the proper functioning and development of red blood cells. A deficiency can occur due to various reasons such as malabsorption, dietary insufficiency, or certain medical conditions affecting absorption in the gastrointestinal tract. Similarly, folate is necessary for DNA synthesis and is particularly important during periods of rapid cell division and growth, such as pregnancy or during certain health conditions. A lack of folate can similarly result in the production of large, malfunctioning red blood cells.

Because both vitamin B12 and folate deficiencies can lead to macrocytic anemia, the most comprehensive and accurate answer encompasses both B and C, affirming that deficiencies in either nutrient can cause this condition.