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 suffer from iron deficiency, making it one of the most prevalent nutrient deficiencies in this group. It frequently occurs alongside deficiencies in magnesium, B12, and vitamin D. Doctors typically check for anemia by measuring hemoglobin and hematocrit levels, which assess the amount of iron in the blood. (1) While they diligently diagnose anemia, they often overlook testing for ferritin levels, which measure the body’s iron stores. This means that even if a patient does not have anemia, they could still have low iron stores affecting their thyroid function.

Iron plays a vital role in thyroid hormone function [2], and hypothyroid patients with depleted iron stores deserve special treatment and attention. Addressing iron deficiency can significantly improve thyroid function and alleviate symptoms.

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 essential for the body and is present in all human cells, primarily in red blood cells. It plays a crucial role in producing hemoglobin, a protein that facilitates oxygen transport by red blood cells throughout the body [3].

Iron supplements are crucial in treating anemia, a condition characterized by low levels of healthy red blood cells. Research shows that iron deficiency is the primary cause of anemia, affecting at least 5 percent of women and 20 percent of men.
While most individuals obtain sufficient iron through their diet, some are susceptible to deficiency and may require iron supplements. (4)

Iron also plays an important role in thyroid function, with a direct relationship between iron deficiency and thyroid function. A study published in the official journal of the American Thyroid Association clearly illustrated this connection [5].

Iron is needed to make thyroid hormones [5]. Iron deficiency also causes low free T3 levels, which can contribute to symptoms of hypothyroidism, such as fatigue, weight gain, and cold intolerance(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.

Things to keep in mind about iron deficiency and thyroid function

When TSH levels are high, it indicates low thyroid hormone levels, and when TSH levels are low, it indicates high thyroid hormone levels.

When TSH levels are high, it indicates low thyroid hormone levels; when TSH levels are low, it indicates high thyroid hormone levels. Transferrin, a protein your liver produces, binds and transports iron in blood serum. It shuttles ingested iron from your food throughout your body via your bloodstream. The transferrin saturation test checks how many places on your transferrin can hold iron and how many are doing so. A low transferrin saturation indicates low iron levels in your serum.

Iron is essential for thyroid hormone production because it affects thyroid peroxidase, an enzyme in the thyroid gland. Since iron is heme-dependent, it means that iron is necessary for proper thyroid function. Studies have shown that low-iron alters the effects of iodine supplementation [5]. When this happens, some patients may believe that iodine supplementation doesn’t work, but the real issue is their low iron levels.

Most healthcare providers miss iron deficiency because they only check iron levels if they detect abnormal hemoglobin or red blood cell levels, which are clear indicators of iron deficiency anemia. Since iron studies are not routinely carried out, many patients with hypothyroidism do not realize that sub-optimal iron levels impair their thyroid function.

What is ferritin and how does it affect thyroid function?

Ferritin is a protein that binds with iron and acts as the body’s primary form of iron storage. The body regulates its iron levels by utilizing these stores until they are exhausted. Once the iron stores are depleted, normal iron levels cannot be maintained, leading to anemia.

On the contrary, ferritin levels may decrease before iron levels decline, indicating that intervention is necessary to prevent anemia.

The normal range of ferritin varies by gender, typically ranging from 30 to 300 ng/mL for men and 10 to 200 ng/mL for women [8], although these ranges can vary between laboratories.

The healthy serum ferritin range is typically between 20 and 80 ng/ml, with the ideal range being 40 to 60 ng/ml. Levels below 20 ng/ml strongly indicate iron deficiency, while levels above 80 ng/ml indicate excess iron. Healthcare providers often recommend iron supplementation for individuals below 20 ng/ml of ferritin.

Elevated ferritin levels can signal various conditions, including:

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

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. These tests should include a complete blood count (CBC) that covers iron, ferritin, and transferrin levels, as well as a total iron-binding capacity (TIBC) test to determine your iron levels and storage. With this information, your healthcare provider can assess your inflammation, anemia, hair loss, or other health conditions related to high or low iron and ferritin 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 yogurt 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 high in iron: lean red grass-fed meats, organic chicken, wild salmon, seafood, organic dark green leafy vegetables, beans, lentils, and spinach. Boost iron absorption by consuming foods rich in vitamin C, such as citrus fruits, berries, apples, figs, apricots, bell peppers, and broccoli, with your meals.

Conclusion

Hypothyroid patients frequently experience low iron levels.

Iron plays a crucial role in thyroid function, and insufficient iron levels can lead to symptoms similar to hypothyroidism. Therefore, it is crucial to assess your iron levels within 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