What are potential causes of low mean corpuscular volume (MCV)?

Low mean corpuscular volume (MCV) indicates that red blood cells are smaller than average, which is typically associated with conditions that cause microcytic anemia. Iron deficiency anemia is the most common cause of microcytic anemia, as iron is crucial for hemoglobin synthesis. A deficiency in iron results in smaller, less functional red blood cells. Similarly, thalassemia is a genetic disorder that affects hemoglobin synthesis, leading to the production of smaller red blood cells as well. These two conditions are directly linked to low MCV due to their pathophysiological impact on red blood cell production and maturation.

While the other options may relate to different aspects of hematological health, they do not lead to a decreased MCV. Diseases affecting the liver and kidney can cause a variety of hematological changes, but they are not specifically associated with low MCV. Vitamin C deficiency primarily impacts iron absorption, potentially leading to iron deficiency anemia, but it is not a direct cause of low MCV on its own. Dehydration tends to concentrate the blood and can actually increase MCV, as it affects plasma volume rather than red blood cell size. Thus, focusing on conditions that explicitly lead to microcytic red blood cells makes iron deficiency anemia and