🩸 The Iron–Thyroid Connection: Why Low Iron Can Sabotage Your Thyroid Health

Feeling constantly tired, foggy, or struggling to maintain a healthy weight even though your thyroid results come back “normal”?

Iron might be part of the missing link.

How Iron Supports the Thyroid

Iron is more than a blood-building mineral — it’s an essential co-factor for thyroid peroxidase (TPO), the enzyme responsible for producing thyroid hormones.

Without adequate iron, your thyroid can’t efficiently convert iodine into thyroxine (T4) and triiodothyronine (T3) — the hormones that drive metabolism, energy, and temperature regulation.

In short:

➡️ Low iron = reduced thyroid hormone production.

➡️ Low thyroid function = reduced stomach acid and poor iron absorption.

It’s a two-way street that can easily turn into a cycle of fatigue and sluggish metabolism.

Signs That Iron or Thyroid Imbalance May Be Affecting You

• Persistent fatigue, even after good sleep

• Brain fog and poor concentration

• Cold hands and feet

• Hair thinning or brittle nails

• Low mood

• Slow metabolism or unexplained weight gain

If several of these sound familiar, it’s worth exploring both thyroid and iron status together.

The Role of Ferritin

Ferritin reflects your stored iron, and for optimal thyroid function it often needs to sit higher than the minimum lab range.

While most labs consider 15–30 µg/L “normal,” many women feel best with ferritin between 70–100 µg/L. I would say 50 µg/L should be minimum.

If ferritin is low, even mild hypothyroid symptoms can worsen.

What to Ask For in Testing

Request a comprehensive panel that includes:

• Thyroid: TSH, Free T4, Free T3, and thyroid antibodies (TPOAb, TgAb)

  
  

• Iron studies: Ferritin, Serum Iron, Transferrin Saturation, and TIBC

Looking at both sets of results together gives a clearer picture of how well your thyroid and iron stores are working in sync.

Nourishing Both Iron and Thyroid Health

1. Prioritise iron-rich foods

Lean red meat, chicken thighs, liver, sardines, lentils, chickpeas, pumpkin seeds, and spinach.

2. Pair with vitamin C

Adding citrus, capsicum, or tomatoes to meals improves absorption.

3. Reduce inhibitors

Avoid tea, coffee, or calcium supplements within an hour of iron-rich meals — they block absorption.

4. Support the thyroid nutrients

Ensure adequate zinc, selenium, and iodine from whole foods like eggs, seafood, and Brazil nuts.

5. Address the root cause

If ferritin remains low despite good intake, investigate gut health, inflammation, or heavy menstrual losses — these can all deplete iron.

The Takeaway

Iron and thyroid health are deeply connected. Low iron can make thyroid symptoms worse, and an under-active thyroid can make it harder to absorb and store iron.

Balancing both is essential for restoring energy, focus, and metabolic health from the inside out.

If you suspect either may be out of balance, seek guidance from a qualified practitioner who can assess your full picture and develop a tailored nutrition plan.

If you’re not sure whether your iron or thyroid might be out of balance, please contact me here — I’d love to help you explore it further 🌿