low iron + your fertility.

Written By Jennalea McInnes

why “normal” ferritin might not be optimal for TTC.

One of the most common things I see in clinic with women trying to conceive?

Ferritin levels sitting in the “normal” range… while symptoms and cycles tell a very different story.

Many pathology reference ranges will flag ferritin as “normal” once it’s above 30 µg/L. But for women trying to conceive, this is not an ideal scenario.

When it comes to fertility, ovulation and healthy hormonal communication, I generally like to see ferritin sitting closer to:
50–70 µg/L.

Why? Because iron is not just about preventing anaemia.

Iron plays a major role in:

  • oxygen delivery

  • mitochondrial energy production

  • thyroid function

  • ovulation

  • neurotransmitter production

  • progesterone production

  • and healthy communication between the brain and ovaries.

This is where ferritin becomes incredibly important!!

ferritin, myelin & hormonal communication

Iron and vitamin B12 are both critical for the health of the myelin sheath- the protective coating around your nerves that helps electrical signals travel efficiently throughout your body.

Think of myelin like insulation around electrical wiring.

Without adequate iron and B12, communication slows down.

And when we’re talking about fertility, internal communication matters.

Your brain and ovaries are constantly communicating through hormones:

  • GnRH

  • FSH

  • LH

  • oestrogen (E2)

  • progesterone

Ovulation relies on precise signalling. If communication becomes impaired, delayed or even dysregulated, cycles can shift too.

This is one reason women with low iron often report:

  • delayed ovulation

  • irregular cycles

  • fatigue

  • poor recovery

  • hair loss

  • low mood

  • PMS/PMDD symptoms

  • poor temperature regulation

  • and difficulty conceiving.

low ferritin & delayed ovulation

Emerging research is beginning to support what many clinicians have observed for years.

Studies suggest that ferritin levels below 30 µg/L may delay LH surges by an average of 18 days.

That is significant.

Because the LH surge is what triggers ovulation. No surge = no ovulation.

Or sometimes:

  • delayed ovulation

  • poor ovulation quality

  • shortened luteal phases

  • inconsistent cycles.

Another study published in in 2023 found that women with unexplained infertility were around three times more likely to have ferritin levels below 30 compared to women without fertility concerns.

This doesn’t mean low ferritin is the sole cause of infertility.

But it absolutely suggests iron status deserves more attention in fertility and preconception care.

“but my iron is normal…”

This is the part many women find frustrating. Because often for them -

  • haemoglobin (Hb) is normal

  • iron is “in range”

  • and ferritin is technically above the pathology cut-off.

Meanwhile they feel:

  • exhausted

  • dizzy

  • cold

  • flat

  • emotionally fragile

  • and are struggling to conceive.

Ferritin is your stored iron. And fertility is energetically expensive.

Your body is unlikely to prioritise reproduction if it perceives resources are low.

+ don’t forget B12

B12 matters here too. We need B12 for myelin sheath as well as red blood cell production. Low B12 can contribute to:

  • elevated homocysteine

  • impaired methylation

  • nervous system dysfunction

  • poor egg quality support

  • fatigue

  • neurological symptoms

  • and impaired myelin integrity.

And importantly, you can absolutely be low in B12 even if you eat animal products, especially if you’ve had a baby and or breastfed.

As well as absorption issues, stress, gut dysfunction, medications and low intrinsic factor can all play a role.

supporting iron for TTC

This is never about self-prescribing iron or taking 100mg a day hoping for the best.

Iron supplementation should always be guided appropriately with blood work and taking in to consideration the clients’ diet, any predisposing factors impacting absorption ie Coeliacs.

For many women TTC, improving ferritin may involve:

  • increasing haem-iron intake via the diet

  • improving protein intake

  • improving and supporting their digestion and absorption

  • correcting low B12

  • assessing their copper and vitamin A status

  • reducing excessive endurance training or low energy availability (LEA)

  • managing heavy menstrual bleeding

  • and strategically using supplementation where appropriate.

Fertility is not just about “having a period.” It’s about whether the body has enough resources to:

  • communicate efficiently

  • ovulate effectively

  • support implantation

  • and sustain pregnancy.

And iron status is a much bigger piece of that puzzle than many women realise.

references -

Holzer et al., Frontiers in Endocrinology 2023, Frontiers in Sports and Active Living 2022, StatsPearls hypothalamus physiology. NCBI iron and brain multilevel impacts

Jennalea McInnes
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