What It Measures
MCV measures the average volume of a single red blood cell in femtoliters (fL). It is calculated by dividing the hematocrit by the red blood cell count, reflecting whether red blood cells are smaller, larger, or normal-sized compared to healthy reference values.
Mean Corpuscular Volume (MCV) measures the average size of red blood cells. It is a key component of the complete blood count (CBC) and helps classify anemias as microcytic, normocytic, or macrocytic, guiding diagnosis of nutritional deficiencies, chronic diseases, and bone marrow disorders.
Current Value
What High Means
Elevated MCV (macrocytosis, >100 fL) indicates larger-than-normal red blood cells. Common causes include vitamin B12 deficiency, folate deficiency, alcohol use, hypothyroidism, liver disease, myelodysplastic syndromes, and certain medications (methotrexate, hydroxyurea, anticonvulsants). Macrocytosis impairs oxygen delivery and may signal megaloblastic anemia when accompanied by hypersegmented neutrophils.
Possible Symptoms
Fatigue, weakness, pallor, shortness of breath, dizziness, numbness/tingling in hands and feet (B12 deficiency), cognitive difficulties, glossitis (swollen tongue), diarrhea, mood changes, balance problems
What Low Means
Low MCV (microcytosis, <80 fL) indicates smaller-than-normal red blood cells. The most common cause is iron deficiency anemia, but it also occurs in thalassemia, chronic disease/inflammation, sideroblastic anemia, and lead poisoning. Microcytic cells carry less hemoglobin, reducing oxygen-carrying capacity.
Possible Symptoms
Fatigue, weakness, pallor, shortness of breath, dizziness, cold hands and feet, brittle nails, headaches, poor exercise tolerance, pica (craving non-food items like ice), restless legs
Risk Factors
Iron deficiency anemia, vitamin B12 deficiency, folate deficiency, thalassemia, chronic alcohol use, hypothyroidism, liver disease, myelodysplastic syndromes, chronic kidney disease, lead poisoning, celiac disease, inflammatory bowel disease
Actionable Advice
Supplements
- •Vitamin B12
- •Folate (methylfolate)
- •Iron (if deficient)
- •Vitamin B6
- •Copper
- •Vitamin C (enhances iron absorption)
Diet & Lifestyle
- •Eat B12-rich foods: meat, fish, eggs, dairy, or fortified foods
- •Include folate-rich foods: dark leafy greens, legumes, asparagus
- •If vegetarian/vegan, supplement B12 regularly
- •Limit alcohol consumption as it directly increases MCV
- •Pair iron-rich foods with vitamin C sources for better absorption
- •Get thyroid function checked if MCV is persistently elevated
- •Address gut health issues (celiac, IBD) that impair nutrient absorption
- •Avoid excessive processed foods that are low in micronutrients
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Historical Trend
Resources & Studies
All Readings
| Date | Value | Change |
|---|---|---|
| 2025-09-18 | 86.2 fL | -6.2 |
| 2025-08-25 | 92.4 fL | +4.7 |
| 2025-07-31 | 87.7 fL | +2.8 |
| 2025-06-27 | 84.9 fL | — |