From the Guidelines
The mean corpuscular hemoglobin (MCH) value of 26.8 picograms (pg) is slightly below the normal range, indicating mild hypochromia, and I strongly recommend further evaluation and potential iron supplementation to address this issue, as supported by the most recent study 1. This finding is commonly associated with iron deficiency anemia or thalassemia trait.
- The normal range for MCH is typically 27-33 pg, and a value of 26.8 pg suggests that the red blood cells contain less hemoglobin than normal.
- According to the study published in 2021 1, serum ferritin is the mainstay for assessment of total body iron stores, and low ferritin levels are specific for iron deficiency.
- The study also suggests that combining ferritin and transferrin saturation (TSAT) provides insight into the potential toxicity of elevated ferritin levels and facilitates the diagnosis of absolute and functional iron deficiency.
- I recommend following up with a healthcare provider for further evaluation, including a complete blood count and iron studies (serum iron, ferritin, total iron binding capacity).
- If iron deficiency is confirmed, oral iron supplementation such as ferrous sulfate 325 mg once or twice daily would likely be prescribed, taken on an empty stomach with vitamin C to enhance absorption.
- Treatment typically continues for 3-6 months even after blood values normalize to replenish iron stores.
- Dietary changes to increase iron intake would also be beneficial, including consuming more red meat, beans, spinach, and fortified cereals.
- The hypochromia occurs because without sufficient iron, the body cannot produce adequate hemoglobin, resulting in smaller, paler red blood cells with reduced oxygen-carrying capacity, as discussed in the study published in 2012 1.
From the Research
Mean Corpuscular Hemoglobin (MCH) Levels
- MCH levels are used to diagnose and differentiate various types of anemia, including iron deficiency anemia and combined iron and vitamin B12 deficiency 2.
- A study found that MCH levels were slightly more accurate than mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) in diagnosing empty iron stores in children and young adults 3.
- MCH levels can be used to predict cardiovascular disease in incident dialysis patients, with low MCHC (< 32 g/dL) being independently associated with the incidence of nonatherosclerotic cardiovascular disease 4.
MCH Reference Values
- A study suggested that couples with MCV ≥ 80, MCH < 26, HbA2 < 3.2, and HbF < 3 can be classified as low-risk β-thalassemia group 5.
- However, it is essential to consider the limitations of MCH measurements, as hypo- and hypernatremia can result in inaccurate erythrocyte MCV measurements in vitro, and MCH may be a more reliable parameter in such cases 6.
Clinical Applications
- MCH levels can be used to differentiate between pure iron deficiency anemia and combined iron and vitamin B12 deficiency, with a PLT/MCH ratio parameter having high values when iron deficiency anemia is accompanied by cobalamin deficiency 2.
- MCH levels can be used to monitor the progression of anemia in patients with chronic diseases, such as kidney disease, and to predict the risk of cardiovascular disease 4.