Several factors can affect MCV levels, including nutritional deficiencies (such as vitamin B12, folate, or iron deficiency), certain medications (e.g., chemotherapeutic drugs), ALC ohol abuse, underlying medical conditions (e.g., hypothyroidism, liver disease), genetic disorders (e.g., thalassemia), and bone marrow disorders. It's important to note that MCV is just one component of a comprehensive blood analysis, and further investigations are often required to determine the underlying cause of any abnormalities. A healthcare professional can provide a thorough evaluation based on individual circumstances.