Iron deficiency and BV or aerobic vaginitis

Author: Jessica Lloyd
Senior Vulvovaginal Specialist Naturopath | BHSc(N) | ISSVD, ISSWSH, BSSM, ATMS

Last reviewed: July 30, 2026

Iron is required by our immune system (amongst many other uses) to help protect us against invaders.¹ If you are low in iron (not necessarily anaemic – just on the low side) and suffer from recurrent vulvovaginal infections like bacterial vaginosis or aerobic vaginitis, get your bloods done.

Your iron levels may be (one of) the missing links between solving your BV and there being an underlying contributing cause. The study you want is called an iron study, which looks at the various aspects of your iron storage and levels.

Optimal iron and ferritin levels

Ferritin is the protein that stores iron in your body, while a separate protein called transferrin carries iron around your bloodstream. Serum ferritin is a good marker of how much iron you have in reserve.²

That’s why we test both – you can be high in serum iron, but low in ferritin, which has the same effect in terms of symptoms of low iron. Typical references ranges are:

Iron 10–30 µmol/L
Ferritin 20–300 µg/L

Remember that reference ranges are actually just what most people’s test results were, not any indication of whether your levels are good or bad. The reference ranges use averages of everyone who has been tested, and creates these upper and lower reference ranges. That’s why they differ between pathology labs.

How much iron is not enough?

If you understand the function of iron in your body, you start to realise that just being within the reference ranges is simply not good enough.

Iron allows oxygen to hop onto your red blood cells and be carried around your body, so if you are on the low or even mid-range of the reference range, your ability to carry oxygen around your body is just at that level.

There is an optimal level, and the reference ranges, and it’s important not to dismiss mid-to-low iron levels as ‘healthy’. It’s just not true. You won’t die, sure, but you won’t feel good either.

Anyone who gets their period loses a lot of iron every time you bleed, so if you bleed heavily or frequently, you lose even more. Heavy periods can also, paradoxically, be a result of low iron.

Signs you could have low iron

Poor immune system, frequent infections
Feel tired a lot or easily
Get tired walking or climbing stairs
Sleep a lot or loooove sleeping
Have low iron intake – don’t eat red meat very often, are vegetarian or vegan, have disordered eating or low food intake overall
When you pull your eyelid down to reveal the conjunctiva, it is pale pink (compare with someone you know has good iron stores)
Pale
Pale conjunctiva of the eye
Restless legs
Feel the cold a lot more than other people, especially hands and feet
Digestive problems that prevent/reduce absorption of nutrients (diarrhoea, IBS, coeliac disease)
Digestive problems involving bacteria that use the iron before it can be absorbed
You are pregnant – you need more iron while you are pregnant, because your blood volume increases
Ridged, spoon-shaped or flat nails
Brittle hair
Memory a bit fuzzy
Reduced thyroid function/thyroid problems

How to decipher your iron blood test results

Serum iron

Serum iron is the level of iron in the sample of blood that was taken.

Serum ferritin

Serum ferritin tells you how much iron is stored in your body.

Transferrin

Transferrin is the protein that transports your iron around the body. If you are low in transferrin, but high in iron, the iron can’t get around your body to be used.

You want to have good levels of both transferrin and iron for the system to work. As transferrin goes about its business in your body, about a third of it is carrying iron, with two-thirds of its capacity reserved.

TIBC – total iron-binding capacity

TIBC is the total amount of iron that can be picked up by proteins in your blood. Transferrin is the main iron-binding protein here, so if your transferrin isn’t doing its job properly, this is the test that will tell you that. TIBC tell you how available your transferrin is in your body.

UIBC – unsaturated iron-binding capacity

UIBC tells you what the reserve capacity of your transferrin is, so the portion of your transferrin that is not used up by circulating iron. UIBC also backs up the transferrin level result.

Transferrin saturation

The sum that reflects how much, percentage-wise, of transferrin is saturated with iron (sum being 100 x serum iron / TIBC).

Study into iron and BV

Researchers looked into iron status of women in early pregnancy, when iron is restricted for reasons that are incompletely understood, as a risk factor for developing bacterial vaginosis.³

The rationale was that even mild deficiencies in nutrients like iron, critical for our immune response against bacterial colonisation, can reduce our ability to stave off colonisation.

The iron status of the study participants was collected in early pregnancy, with 80 women who had healthy vaginal flora and 18 who had vaginosis-like flora.

Study results – does low iron contribute to susceptibility to BV (at least during early pregnancy)? Yes!

The routine iron tests — serum iron, ferritin and transferrin — did not on their own separate the healthy-flora women from the BV-like women. But more sensitive markers of early, functional iron shortfall (the soluble transferrin receptor and the transferrin-receptor to ferritin index) were strongly and independently linked to BV-like flora, with roughly a three-fold increase in risk. In other words, it was subclinical iron deficiency — an early shortfall that does not yet show as anaemia — rather than obvious anaemia that tracked with disturbed flora.³

The conclusion by the researchers was that subclinical iron deficiency is strongly and independently associated with vaginosis-like microflora during early pregnancy.

Frequently asked questions

Can low iron make BV more likely?

In a study of women in early pregnancy, subclinical iron deficiency — an early shortfall that does not yet show as anaemia — was strongly and independently linked to BV-like vaginal flora. Iron matters for the immune defences that help keep vaginal bacteria in balance.³

What iron test should I ask for?

Ask for a full iron study, which reports serum iron, ferritin, transferrin, TIBC and transferrin saturation together, rather than a single iron reading. Ferritin (your iron stores) is often the most useful number.

What are good iron and ferritin levels?

Typical Australian reference ranges are roughly 10–30 µmol/L for serum iron and 20–300 µg/L for ferritin, but being ‘within range’ is not the same as optimal — low-normal stores can still leave you feeling unwell.

This article is general information and not a substitute for personalised medical advice. If you have recurrent vaginal infections and suspect low iron, please see an experienced practitioner for iron studies.

Cassat JE, Skaar EP. Iron in infection and immunity. Cell Host & Microbe. 2013;13(5):509–519.
Anderson GJ, Frazer DM. Current understanding of iron homeostasis. American Journal of Clinical Nutrition. 2017;106(Suppl 6):1559S–1566S.
Verstraelen H, Delanghe J, Roelens K, Blot S, Claeys G, Temmerman M. Subclinical iron deficiency is a strong predictor of bacterial vaginosis in early pregnancy. BMC Infectious Diseases. 2005;5:55.