From the Guidelines
Slightly low MCV and MCH in a healthy 30-year-old male typically suggests mild microcytic hypochromic anemia, most commonly caused by iron deficiency or thalassemia trait, and I recommend getting a complete blood count with iron studies, including ferritin, serum iron, total iron binding capacity, and transferrin saturation, as the first step in management. According to the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1, iron deficiency is a common cause of microcytic hypochromic anemia, and serum ferritin concentration is the most specific test for iron deficiency. The guidelines suggest that an SF level of <15 μg/L is indicative of absent iron stores, while SF levels of less than 30 μg/L are generally indicative of low body iron stores 1. Some key points to consider in the management of slightly low MCV and MCH include:
- Getting a complete blood count with iron studies to confirm iron deficiency
- Considering hemoglobin electrophoresis to check for thalassemia trait if iron studies are normal
- Taking an oral iron supplement such as ferrous sulfate 325 mg once or twice daily with vitamin C to enhance absorption if iron deficiency is confirmed
- Avoiding taking iron with calcium, dairy, coffee, tea, or antacids as these reduce absorption
- Making dietary changes to increase iron intake, such as consuming more red meat, beans, spinach, and fortified cereals alongside vitamin C-rich foods to improve absorption. It is also important to note that the specificity of MCV and MCH for iron deficiency is limited, as microcytosis and hypochromia also occur in many haemoglobinopathies, sideroblastic anaemia, and some cases of anaemia of chronic disease 1. However, the most recent and highest quality study 1 suggests that serum ferritin concentration is the most powerful test for iron deficiency, and an SF cut-off of 45 μg/L provides a respectable specificity of 0.92 for iron deficiency.
From the Research
Slightly Low MCV and MCH in a Healthy 30-Year-Old Male
- A slightly low Mean Corpuscular Volume (MCV) and Mean Cell Hemoglobin (MCH) can be indicative of microcytic anemia, which is characterized by small, often hypochromic, red blood cells in a peripheral blood smear 2.
- The most common cause of microcytic anemia is iron deficiency, which can be diagnosed by measuring serum ferritin, iron concentration, transferrin saturation, and iron-binding capacity 2.
- However, a study found that MCH, MCV, and MCHC are only moderately accurate in diagnosing empty iron stores in children and young adults, and normal values of these tests do not exclude empty iron stores in anemic patients 3.
- Another study suggested that the platelet count/mean corpuscular hemoglobin ratio can distinguish combined iron and vitamin B12 deficiency from uncomplicated iron deficiency 4.
- A study on blood donors found that iron deficiency anemia (IDA) and α-thalassemia are the most common causes of microcytosis, and that haematological parameters such as haemoglobin, MCV, MCHC, and MCH can be useful in differentiating between the different types of microcytic anemia 5.
- It is essential to investigate the cause of anemia to provide appropriate treatment, and a thorough history and physical examination, complete blood cell count (CBC), and supplemental tests such as a peripheral blood smear and iron panel may be necessary 6.