🦋 The Endocrine System: Supporting the Thyroid with Selenium, Iodine and Tyrosine
Three nutrients important for the thyroid — what of this is really needed
The thyroid is a key organ of the endocrine system. It regulates metabolism, energy, temperature and much more. Its function depends on several nutrients, among which iodine, selenium and tyrosine hold a special place.
There is a lot of myth and supplements around "thyroid support". Let's look at the real role of iodine, selenium and tyrosine, when they are lacking and what actually makes sense.
How the thyroid works
The thyroid produces hormones T4 and T3, which regulate metabolism. Their synthesis and activation depend on iodine, selenium and tyrosine.
Basis of hormones
Part of the structure of thyroid hormones.
Activation
Needed to convert T4 into active T3.
Building material
The amino acid from which hormones are built.
Iodine: the basis of thyroid hormones
Iodine is a key element for the synthesis of thyroid hormones. Its deficiency is one of the most common causes of thyroid problems in the world.
Selenium: hormone activation
Selenium is an important mineral for the thyroid. It participates in converting T4 into active T3 and protects the gland from oxidative stress.
| Food | Selenium content |
|---|---|
| Brazil nut | Very high |
| Tuna | ~90 mcg/100 g |
| Eggs | ~30 mcg/100 g |
| Sunflower seeds | ~50 mcg/100 g |
Tyrosine: building material
Tyrosine is an amino acid from which the body builds thyroid hormones. It is also a precursor to dopamine and norepinephrine.
Norms and balance
Nutrient balance matters more than taking each one separately.
| Nutrient | Norm/day | Role |
|---|---|---|
| Iodine | ~150 mcg | Hormone synthesis |
| Selenium | ~55 mcg | T3 activation, protection |
| Tyrosine | From protein | Building material |
Foods for the thyroid
You can support the thyroid through nutrition.
| Nutrient | Foods |
|---|---|
| Iodine | Sea fish, seaweed, iodized salt |
| Selenium | Brazil nuts, tuna, eggs |
| Tyrosine | Meat, fish, eggs, legumes |
What really matters
How to sensibly approach thyroid support.
Diagnosis first
A test for TSH, T4, T3 and, if needed, antibodies. Do not self-treat without a test.
Iodine and selenium balance
Both matter. Excess of one without the other can be harmful.
Adequate protein
Tyrosine comes with protein foods. The diet usually covers the need.
Correction as prescribed
Iodine and selenium deficiencies are replenished by test results and under a doctor's control.
Why does the thyroid need iodine?
Iodine is part of the structure of hormones T4 and T3. Without iodine the gland cannot produce them.
How does selenium affect the thyroid?
Selenium participates in converting T4 into active T3 and protects the gland from oxidative stress.
What is tyrosine?
An amino acid from which the body builds thyroid hormones. Also a dopamine precursor.
How much iodine per day?
About 150 mcg for adults. Sources — sea fish, seaweed, iodized salt.
Can I take iodine without a test?
Excess iodine is dangerous. Take it only as prescribed and after a status check.
Is selenium excess harmful?
Yes, selenium overdose is toxic. Do not overdo Brazil nuts and supplements.
Which foods are rich in iodine?
Sea fish, seaweed, iodized salt, seafood.
How to check thyroid function?
A blood test for TSH, T4 and T3. If pathology is suspected — an endocrinologist consultation.
Is tyrosine needed as a supplement?
Usually no — tyrosine comes from protein foods. Deficiency is rare.
What to do with hypothyroidism?
Treatment is prescribed by a doctor. Iodine/selenium supplements do not replace therapy and are taken as prescribed.