MCV value in women: the same range, different causes

The MCV value in women sits between 80 and 100 fl, exactly the same reference range as in men. A separate female range does not exist. What does differ is how likely each cause is: in women of reproductive age, an MCV towards the low end is far more often an iron story.

That sounds like a detail. It is the difference between a result that reassures you and a result that tells you something.

Why there is no separate MCV value for women

Dutch laboratories use one MCV reference range for everyone, roughly 80 to 100 fl. If your result sheet does print a male and a female column, look at the numbers: for MCV both columns carry the same ones. For haemoglobin and haematocrit those numbers genuinely differ. That follows from how small the measured sex difference in MCV is.

One South Korean hospital analysed almost a million blood counts from patients without anaemia. The sex gap there reached about 1.1 fl in the over-eighties (PMID 35599236). Below the age of forty, the value in women actually ran slightly higher than in men.

A difference like that falls inside the noise of an ordinary cell counter. A female-only range would be false precision.

So compare your value with the range printed beside your own result, not with a table you found elsewhere. What the value measures is explained under MCV.

Why a low MCV value is more common in women

Because women lose blood every month. According to the Dutch NHG anaemia guideline, 14.6 per 1,000 women aged 25 to 44 develop iron deficiency anaemia each year. Recurrent blood loss accounts for 94 percent of all iron deficiency anaemia (PMID 41252836). In this age group, menstruation is its most common source.

Iron leaves your body with every period, and your stores refill more slowly than they empty. Red blood cells built with too little iron come out of the bone marrow smaller. Your MCV therefore often drops before your haemoglobin does.

The NHG guideline puts ferritin next in line for microcytic or normocytic anaemia, with a ferritin below 15 micrograms per litre pointing to iron deficiency. The same guideline also lists ferritin separately, for unexplained fatigue in women of childbearing age.

What that number means sits under ferritin.

What fits which MCV value in women?

The three tracks are the same for everyone, but the order of likelihood differs in women. Below 80 fl it is usually about iron. Above 100 fl it is more often vitamin B12 or folate. And in between sits the category where most results land.

Read this table as a direction, not a diagnosis. MCV points at a track; it does not establish anything by itself.

What your MCV says with heavy periods

With heavy menstrual blood loss, an MCV towards the low end is one of the first things that stands out in a blood count. Cells shrink before their number falls, so you can have a low MCV while your haemoglobin still sits neatly inside the range.

Picture this: you are 31, your period lasts seven days, and on weekdays you have to combine tampons and pads. Your haemoglobin is normal, your MCV is 78 fl and your ferritin is 8. There is no anaemia, and yet your iron stores are empty.

That is exactly why the two are worth reading together. When a period counts as genuinely heavy, and what you can measure then, sits in the article on heavy periods.

Does your MCV change in pregnancy?

Yes, but only a little. Reference tables for pregnant women list a somewhat higher mean cell volume per trimester than outside pregnancy (PMID 19935037). Haemoglobin moves the other way over the same months, because plasma volume expands. An MCV that shifts by a few femtolitres in pregnancy therefore fits the normal picture.

So the two move in opposite directions. That makes a result in pregnancy harder to read, and your midwife or GP weighs the values against gestational age. How iron, ferritin and haemoglobin fit together in that period sits in the article on anaemia in pregnancy.

A high MCV value in women: B12, diet and metformin

Above 100 fl, two causes come into view more often in women than the rest. The first is a vitamin B12 shortfall in people who eat vegetarian or vegan. In a review of eighteen studies, deficiency rates among vegetarians varied widely, with 62 percent among pregnant women as the highest figure (PMID 23356638).

The second is long-term metformin use, which many women with PCOS or diabetes take. In the Diabetes Prevention Program Outcomes Study, 4.3 percent of users had a low B12 after five years, against 2.3 percent on placebo. Each additional year of use raised that risk further (PMID 26900641).

A B12 shortfall makes red blood cells larger, so a high MCV can show it before you notice anything. What B12 does and when measuring makes sense sits under vitamin B12.

The pitfall: two deficiencies that cancel each other out

A normal MCV is no proof that nothing is missing. If you lose iron every month and are short on B12 at the same time, you make both undersized and oversized red blood cells. Their average lands right in the middle, so your result looks calm while two things are going on at once.

This is the most important blind spot of this value. In women who menstruate and eat few animal products, that combination is realistic. So with a perfectly normal MCV I always ask two further questions: about periods, and about diet.

The value that gives it away is RDW, the spread in cell size. Two groups of differently sized cells average out to normal, but the spread is usually raised. So never read your MCV without RDW.

When do you take your MCV to your GP?

As soon as your MCV falls outside the range on your own result, or as soon as symptoms come with it. A value sitting just under or just over the limit is not an alarm by itself. Combined with fatigue, heavy blood loss or an abnormal haemoglobin, it does deserve a conversation. Your GP weighs the number against your story.

Take it in at least in the following cases:

• your MCV falls outside the range printed on your own result;
• symptoms persist, such as fatigue, breathlessness, palpitations or hair loss;
• your periods are heavy or long;
• your MCV is low and you no longer menstruate.

That last point carries weight. After menopause the monthly explanation has fallen away, so a low MCV always deserves attention.

Do not start iron or B12 on your own off a single result. Supplements change the blood count and can blur the picture before anyone has looked at where the loss comes from.

To follow your iron stores alongside your blood count, you can use the ferritin test. The result is reviewed by a doctor registered in the Dutch BIG register.

References

1. Lee JY, Choi H, Park JW, et al. Age-related changes in mean corpuscular volumes in patients without anaemia: an analysis of large-volume data from a single institute. J Cell Mol Med. 2022;26(12):3548-3556. PMID 35599236.
2. Latimer K, Baci G, Layne M. Iron deficiency anemia: evaluation and management. Am Fam Physician. 2025;112(5):538-545. PMID 41252836.
3. Aroda VR, Edelstein SL, Goldberg RB, et al. Long-term metformin use and vitamin B12 deficiency in the Diabetes Prevention Program Outcomes Study. J Clin Endocrinol Metab. 2016;101(4):1754-1761. PMID 26900641.
4. Pawlak R, Parrott SJ, Raj S, Cullum-Dugan D, Lucus D. How prevalent is vitamin B12 deficiency among vegetarians? Nutr Rev. 2013;71(2):110-117. PMID 23356638.
5. Abbassi-Ghanavati M, Greer LG, Cunningham FG. Pregnancy and laboratory studies: a reference table for clinicians. Obstet Gynecol. 2009;114(6):1326-1331. PMID 19935037.
6. NHG (Dutch College of General Practitioners). NHG guideline on anaemia. Accessed 2026.

Every blood test result at Lunara includes a professional assessment by a doctor registered in the Dutch BIG register. This article gives general information and does not make a diagnosis. For treatment decisions, discuss your results with your GP.