Iron (Thyroid Support)

An essential mineral required for thyroid peroxidase enzyme function and thyroid hormone synthesis.

Also known as: Ferrous Bisglycinate • Iron Bisglycinate • Fe

other Names
Ferrous Bisglycinate, Iron Bisglycinate
primary Benefits
TPO enzyme function, thyroid hormone synthesis, oxygen transport
common Dose
18-36 mg daily (elemental iron)
best Form
Iron bisglycinate (gentle, well-absorbed)
timing
On empty stomach or with vitamin C
safety Rating
Safe (test levels first)

Overview

Iron is a critical cofactor for thyroid peroxidase (TPO), the enzyme responsible for iodinating tyrosine residues to form thyroid hormones. Iron deficiency impairs thyroid hormone synthesis and is a common but overlooked cause of persistent hypothyroid symptoms. Women of reproductive age are particularly at risk for both iron and thyroid deficiency.

Key Benefits

TPO Enzyme Function

Iron is a cofactor for thyroid peroxidase, essential for thyroid hormone synthesis.

Thyroid Hormone Production

Iron deficiency directly impairs the thyroid's ability to produce T3 and T4.

Oxygen Transport

Hemoglobin requires iron to deliver oxygen to all tissues including the thyroid.

Energy Production

Iron is essential for mitochondrial energy production and cytochrome enzymes.

Dosage & How to Take

18-36 mg elemental iron daily (if deficient).

PurposeDoseNotes
Mild deficiency18-25 mg/dayBisglycinate form
Moderate deficiency25-36 mg/dayWith vitamin C for absorption

Best Time to Take

On empty stomach or with vitamin C.

With or Without Food

Best on empty stomach; take with vitamin C to enhance absorption.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Iron BisglycinateHighGentle on stomach, well-absorbedChelated form with fewer GI side effects.
Ferrous SulfateModerateBudget optionMore GI side effects.

Side Effects & Safety

Common

  • Constipation
  • Dark stools
  • Nausea

Rare

  • Iron overload (hemochromatosis)

Contraindications

  • Hemochromatosis
  • Iron overload conditions
  • Do not supplement without testing

Interactions

Thyroid medicationsModerate

Iron reduces levothyroxine absorption; separate by 4 hours.

CalciumModerate

Calcium inhibits iron absorption; separate doses.

Scientific Research

2006Journal of Clinical Endocrinology & Metabolism

Iron deficiency and thyroid function

Studies showed iron deficiency impairs thyroid hormone synthesis and that iron supplementation improves thyroid function in iron-deficient women.

Food Sources

Red meat
Liver
Spinach
Lentils
Fortified cereals

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.