Iron Deficiency and Thyroid Function

Table of Contents

Do you know that there is a link between iron deficiency and thyroid function? Yes. It has been proven that iron deficiency may be one of the reasons why your thyroid symptoms cannot be controlled, even while you’re on thyroid medication.

Most hypothyroid patients experience iron deficiency. In fact, it is one of the most common nutrient deficiencies that occur in hypothyroid patients.

It occurs alongside magnesium deficiency, B12 deficiency, and vitamin D deficiency.

But apart from being common, many doctors frequently misdiagnose this condition, and there’s an important reason why they do so:

Most doctors by default test the patient for iron deficiency anemia [1].

They are always on the lookout for this condition, so they rarely miss this diagnosis. But they always forget to check for ferritin levels.

To evaluate your thyroid function, measuring your iron stores rather than your serum iron levels is more important and helpful.

Hypothyroid patients deserve special treatment and attention if their iron stores are depleted because of iron’s vital role in thyroid hormone function [2].

In this article, we’ll get to learn all about Iron deficiency and thyroid function :

The importance of iron in thyroid function
What ferritin is and how it affect thyroid function
The importance of knowing your iron levels and ferritin levels
The health implications of a very low or extremely high ferritin level
Symptoms of low and high iron levels
The link between low iron or high/ferritin levels and hair loss
How can your diet contribute to a high or low iron level?
What you can do if you have too little iron.

The importance of Iron in Thyroid Function

Iron is a very important mineral for the body. Iron is present in all human cells, but most of it is found in the red blood cells. Your body produces hemoglobin with the aid of iron. Hemoglobin is a protein that helps your red blood cells to transport oxygen to all parts of the body [3].

When someone is anemic, they could take iron supplements. (i.e., has very low levels of healthy red blood cells). Studies have shown that iron supplements play an important role in treating anemia. In most cases, a person can get all the iron they need from their diet. But in some cases, one may be prone to iron deficiency. Iron deficiency is the most common cause of anemia, and it occurs in at least 5 percent of women and 20 percent of men [4].

Iron plays an important role in thyroid function, there is a direct relation between iron deficiency and thyroid function. This has been clearly illustrated in a study published in the official journal of the American Thyroid Association [5].

Thyroid hormone is made with the help of iron. [5], but iron deficiency also indicates low free T3 levels [6].

It is important for any thyroid patient to know that T3 is the single most important and potent thyroid hormone in the body.

When you’re deficient in iron, your body will be unable to produce as much T3 as it should.

This explains the persistent symptoms of hypothyroidism in patients who take their thyroid hormone medication.

The figure below explains the link between iron and thyroid-stimulating hormone levels. The study from which this graph was taken was published by Khatiwada et al., in the journal Thyroid Research [7].

This figure clearly illustrates the inverse relationship that occurs between TSH and transferrin saturation. It regulates the absorption of iron into your blood. Transferrin binds to iron and transports it across your body.

As indicated in the graph, a fall in transferrin saturation translates to an increase in TSH which is an indicator of hypothyroidism.

Things to keep in mind about iron deficiency and thyroid function

Note:

When TSH is high, it means that the thyroid hormones are low, and when TSH is low, it means thyroid hormone levels are high.

Transferrin is a protein produced by your liver that binds and transports iron in blood serum. It is the primary iron-binding protein that shuttles ingested iron from the food you eat throughout your body via your bloodstream. The transferrin saturation test is a medical laboratory value. It checks the number of places on your transferrin that can hold iron are actually doing so.

A low transferrin saturation indicates that the level of iron in your serum is low.

Iron is involved in thyroid hormone production. It has far-reaching effects on thyroid peroxidase. Thyroid peroxidase is an enzyme that is found in the thyroid gland. What was said there is a link between iron deficiency and thyroid function.

Heme-dependent means iron-dependent. In other words, when something is heme dependent, it means that it requires iron to function properly.

What’s more, studies have shown that low-iron alters the effects of iodine supplementation [5].

This means that low iron levels drastically limit your chances of utilizing iodine supplements.

When this happens, some patients may think that iodine supplementation doesn’t work, but the fact is, their iron status is at fault.

What worsens the entire situation is that most healthcare providers usually miss the part about iron deficiency.

Most doctors will only check your iron levels if they discover that you have abnormal hemoglobin levels or red blood cell levels – which is a clear indication of iron deficiency anemia.

And since iron studies are not routinely carried out, many patients with hypothyroidism do not even realize that their thyroid function is impaired by sub-optimal iron levels.

What is ferritin and how does it affect thyroid function?

Ferritin is a protein that binds with iron and serves as the primary form of iron storage by the body. The body maintains its iron levels by drawing on the iron stores until they are completely used up. After the iron stores are depleted, iron can no longer be maintained at its normal levels and will start depleting. The affected person will eventually develop anemia.

On the other hand, ferritin levels may deplete before iron levels fall: low ferritin levels are a sign that an intervention is needed to prevent anemia.

The normal range of ferritin for men is 30 to 300 ng/ml and 10 to 200 ng/ml for women [8]. However, these reference ranges may vary across laboratories. Many healthcare providers believe that iron supplementation is necessary for anyone whose ferritin level is below 60 mg/dL.

The aim of supplementation is to raise ferritin levels to 70 to 90 mg/dL. Serum ferritin is considered healthy within the 20 and 80 ng/ml range. However, the ideal range is between 40 to 60 ng/ml. If your serum ferritin level is above 80, then you most likely have an iron surplus. A higher than normal ferritin level occurs in several conditions. But then, diagnosis of these conditions may require further testing based on physical examination and your symptoms.

Porphyria
Hemochromatosis
Taking excess iron supplements
Hyperthyroidism
Alcohol abuse
Multiple blood transfusions
Liver disease
Hodgkin’s lymphoma

If your ferritin levels are low, consider topping your diet with iron-rich foods.

The link between low ferritin and thyroid function

It is important to note that hypothyroidism causes reduced levels of hydrochloric acid in the stomach, which in turn leads to poor iron absorption [9].

Low ferritin levels are problematic for hypothyroid patients for several reasons.

Firstly, an adequate supply of iron is necessary for normal thyroid hormone metabolism [6]. Normal thyroid hormone metabolism also depends on adequate supplies of zinc, selenium, and iodine [6]. It is important to note that zinc and iron interact in the intestine. This interaction is highly competitive. An excess of iron inhibits zinc absorption, while an excess of zinc inhibits iron absorption as well.

It is also important to note that symptoms of anemia bear a close semblance to symptoms of hypothyroidism, so the patient may believe that they are not taking adequate thyroid medication or that what they are taking isn’t effective.

For instance, hair loss is a symptom of hypothyroidism, but it may also be caused by iron deficiency [10, 11]. Many patients may believe that their hair loss is a sign of hypothyroidism completely unaware of the fact that they may have very low levels of iron/ferritin. It is mandatory that all hypothyroid patients get tested for ferritin/iron.

Thirdly, iron deficiency may result in the deactivation of the thyroid peroxidase enzyme. The thyroid peroxidase enzyme is iron-dependent, so its deactivation may reduce thyroid hormone production. There may be an alteration of thyroid metabolism as well, while the conversion of thyroxine (T4) into triiodothyronine (T3) may be slowed down, and the binding of T3 modified. There may also be an increase in the circulating levels of thyroid-stimulating hormone [5].

Clinical studies have also shown that levothyroxine treatment may be beneficial to patients with anemia and subclinical hypothyroidism [12].

So, it is important that patients with hypothyroidism undergo regular checks on their ferritin and iron levels as a deficiency in this mineral can cause complications for these patients [13].

The importance of knowing your levels of iron and ferritin for your thyroid health

Knowing the amount of ferritin in your blood can give your doctor an idea about your overall iron levels. The higher the amount of ferritin in your blood, the more stored iron in your body,

Low ferritin levels are associated with the following symptoms:

Dizziness
Unexplained fatigue
Chronic headaches
Ringing in the ears
Leg pains
Irritability
Shortness of breath

High ferritin levels may also cause unpleasant symptoms, such as:

Joint pain
Stomach pain
Chest pains or heart palpitations
Unexplained fatigue

High ferritin levels may also be due to organ damage, such as damage to the spleen and liver.

A ferritin test can also monitor your health, especially if you have an iron-related condition. High levels of ferritin can indicate inflammation in the body. Ferritin is a marker of acute and chronic inflammation. Ferritin levels are elevated in a wide range of inflammatory conditions such as cancer, acute infections, rheumatoid arthritis, and other autoimmune conditions.

What tests should you take?

Annual blood tests are essential. The tests would include a complete blood count (CBC) that includes iron, as well as ferritin and transferrin, and a total iron-binding capacity (TIBC) test to know your iron levels and storage. With this information, your healthcare provider will be able to know if you have inflammation, anemia, hair loss, and other health conditions that may be attributed to high or low iron levels.

How a high or low ferritin level can affect your health

Hyperthyroidism and high levels of ferritin

An overactive thyroid interferes with iron metabolism and produces a high amount of ferritin. So, if you have hyperthyroidism, it is likely that your ferritin levels are on the high side.

Hypothyroidism and low levels of ferritin

We have established that most conventional doctors rarely order the ferritin test so many patients are left with the symptoms of hypothyroidism when in fact their health problems are caused by low ferritin levels. The first problem with iron is that one may be having severe iron deficiency but blood markers such as the red blood cell count and hemoglobin may be normal. and so many patients, mostly women are left misdiagnosed as non-anemic.

What causes iron deficiency and low ferritin?

Iron deficiency and low ferritin are caused by a lifelong history of blood loss mainly attributed to blood donations, menstrual bleeding, surgeries, pregnancies, atrophic gastritis, accidents, celiac disease, and antacid medications (calcium carbonate). If you have issues with your gut that are causing nutrient malabsorption, then your ferritin levels may be low as well. A vegan/vegetarian, or high-level athlete may also be at risk for low iron. These can cause excessive iron loss and poor iron absorption, resulting in low ferritin levels.

Do you know that high or low levels of iron and ferritin can cause hair loss?

We have established that iron is involved in many vital bodily processes including the creation of red blood cells.

Red blood cells help in the transportation of oxygen to various tissues and organs of the body. This can cause several problems including hair loss.

A study published in the Journal of Korean Medical Science found that generally, people who had pattern hair loss were deficient in iron compared to those who did not [10].

This claim has been backed up by other smaller studies. For example, a study published in the Indian Journal of Health Sciences and Biomedical Research found low serum ferritin levels in women with hair loss problems, implying that they were deficient in iron [14].

One reason why iron deficiency leads to hair loss is that when your iron level is low, the body takes the ferritin stored in the hair follicles and uses it in another part of the body. The reduced level of ferritin causes the hair to weaken, leading to hair loss.

Iron is an essential nutrient. This means that it can only be obtained through the diet. So, a person’s risk of low ferritin levels increases if they do not eat iron-rich foods. So, diet is an important factor in the link between iron deficiency an thyroid function.

Factors that may affect the concentration of ferritin in the serum include:

Exercise habits
Smoking
Ethanol (alcohol) intake
Diet

Does increasing ferritin levels help?

If your hair loss is due to low ferritin levels, then theoretically, upping your iron intake should replenish the ferritin in your hair follicles. Your healthcare provider will prescribe iron supplements and then observe your symptoms.

Conversely, raising ferritin levels will not have any positive effect on hair growth in healthy people who have normal ferritin and iron levels.

It is also worth knowing that too much iron may have side effects, including iron poisoning as well as tissue and organ damage, and may trigger inflammatory processes in the body.

Metals in dental work can also contribute to high iron and ferritin levels

Heavy metal poisoning is attributed to the accumulation of certain metals in the body due to exposure to industrial chemicals, water, food, or other sources.

Yes, the human body needs small amounts of specific metals (manganese, iron, chromium, copper, and zinc) to function normally, but these metals become harmful in toxic amounts.

If the soft tissues of your body accumulate an excess of these substances, the resulting toxicity can cause serious health problems.

As you know I am a hypothyroidism patient. I have been experiencing high levels of Iron and ferritin for some time, and my naturopathic doctor recommended I donate blood to lower my levels. Every time I donated blood, my levels drop too low, resulting in hair loss.

My doctor couldn’t identify why I had these high iron levels until I went to the dentist for a check-up. They discovered that I had a small cavity hidden inside a crown made of a combination of porcelain and metal. In total I had five dental crowns in my mouth that were leaching the metals into my blood, causing high levels of Iron and ferritin. I am in the process of replacing all my crowns and looking forward to testing my Iron again to see if my levels are optimal.

How can your diet contribute to a high or low iron level?

Recommendations to reduce high iron levels

Foods that block Iron from your food

Organic low-fat yogourt or grass-fed raw cheese (feta cheese, parmesan cheese, goat cheese)
Foods with tannins: coffee, tea, etc
Foods that contain phytates or phytic acids, such as brown rice and whole-grain foods.
Decreasing your intake of iron-rich foods like red meats from cow, lamb, and seafood, and eliminate iron–rich fortified foods.
Avoid taking foods high in vitamin C or supplements with meals high in Iron

Other recommendations to reduce the iron and ferritin levels:

Change your cookware to ceramic.
Take turmeric supplements after your meals with iron-rich foods.
Donate blood if you have too high levels of Iron and Ferritin

What you can do if you have too little Iron

Taking supplements or eating foods with high vitamin C content with your meals will help absorb Iron.
Eat foods with high levels of Iron: lean red grass-fed meats, organic chicken, wild salmon, and seafood, organic dark green leafy vegetables, figs, apricots, etc.

Conclusion

Hypothyroid patients frequently experience low iron levels.

Iron plays an important role in thyroid function in the body, and sub-optimal iron levels can trigger symptoms that may mimic the symptoms of hypothyroidism.

And so, it is important that you evaluate your iron levels taking into consideration the optimal ranges.

If you have hypothyroidism and you also think that your iron levels are below optimal, then start by getting a full iron lab test panel.

Iron supplementation may help boost thyroid function by increasing T4 to T3 conversion and enhancing the effect of your thyroid medication.

And while checking your iron levels, also remember to check whether you’re deficient in other nutrients, such as vitamin B12, D, selenium, zinc, and magnesium. They are also common in hypothyroid patients.

References

Warner MJ, Kamran MT. Iron Deficiency Anemia. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448065/
Li S, Gao X, Wei Y, Zhu G, Yang C. The Relationship between Iron Deficiency and Thyroid Function in Chinese Women during Early Pregnancy. J Nutr Sci Vitaminol (Tokyo). 2016;62(6):397-401. doi:10.3177/jnsv.62.397
National Institutes of Health Office of Dietary Supplements. Iron.
Johnson Wimbley TD. Diagnosis and management of iron deficiency anemia in the 21st century. Therp Adv Gastroenterol. 2011; 4(3): 177-184. doi: 10.1177/1756283X11398736
Zimmermann MB, Köhrle J. The impact of iron and selenium deficiencies on iodine and thyroid metabolism: biochemistry and relevance to public health. Thyroid. 2002;12(10):867-878. doi:10.1089/105072502761016494
Eftekhari MH, Keshavarz SA, Jalali M, Elguero E, Eshraghian MR, Simondon KB. The relationship between iron status and thyroid hormone concentration in iron-deficient adolescent Iranian girls. Asia Pac J Clin Nutr. 2006;15(1):50-55.

MY THYROID RELIEF