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Can MTHFR affect your thyroid and be a root cause of Hashimoto’s disease?

Can MTHFR affect your thyroid and be a root cause of Hashimoto’s disease?

Can MTHFR affect your thyroid and be a root cause of Hashimoto’s disease?

Thyroid Disorders, such as Hashimoto’s Disease, affect 10 times more women than men,in Perth, Australia and worldwide. Thyroid Disorders, especially hypothyroidism – or an underactive thyroid gland – become more common as we grow older. Iodine deficiency has re-emerged in Australia and we can expect more people to suffer from swelling and enlargement of the thyroid gland, also known as a goiter. 1

There is plenty of discussion surrounding what causes thyroid dysfunction. We know that any issues with your thyroid affects the whole body and results in a range of symptoms. These symptoms vary in seriousness, from frustrating to preventing you from enjoying your daily life.

But what do we know about thyroid dysfunction and its correlation to MTHFR? Can it be a cause of Hashimoto’s disease? If so, what is the thyroid treatment best for you?

If you are trying to manage a condition like Hashimoto’s hypothyroidism, it’s important that you are able to reduce inflammation and raise your glutathione levels. An MTHFR mutation can be interfering with both, as well as causing your Hashimoto’s disease.

Let’s start with gaining an understanding of MTHFR.

What is MTHFR? 

MTHFR, or methyltetrahydrofolate reductase, is the name of both the gene and the enzyme that the gene produces. The enzyme is used to convert folic acid and folate into a form that the body can use, i.e. methylfolate, which is important for numerous biological processes. 

Your MTHFR composition is dependent upon the two genes from your parents. Depending on whether you inherited zero, one or two MTHFR SNPs (pronounced snips), functioning may be reduced by as much as 30 to 70 percent. 

Methylation is also required for:

  • Repairing damaged cells, as well as ensuring optimal protein and DNA cell function
  • Coenzyme Q10, creatinine, melatonin, phosphatidylcholine and carnitine synthesis – since mitochondria depend on these compounds, energy and immune processes are also impacted 
  • Glutathione production, the body’s primary antioxidant
  • Breaking down chemicals and toxins
  • Metabolizing B-vitamins, neurotransmitters, and hormones
  • Regulating dopamine, serotonin, and norepinephrine, which influence sleep, behaviour and cognitive abilities 2

What causes Thyroid issues such as Hashimoto’s Disease?

The thyroid gland hormones regulate metabolism in every cell in the body. The two most common thyroid dysfunctions are hypothyroidism and hyperthyroidism.

The most common autoimmune cause of thyroid problems is Hashimoto’s disease. Hashimoto thyroiditis is thought to result from a combination of genetic and environmental factors.

Other common thyroid conditions

Hypothyroidism is the underproduction of the thyroid hormones T3 and T4.

Hypothyroid disorders may occur as a result of:

  • Congenital thyroid abnormalities (thyroid deficiency at birth)
  • Autoimmune disorders such as Hashimoto’s disease
  • Iodine deficiency 
  • Removal of the thyroid following surgery to treat severe hyperthyroidism and/or thyroid cancer 3

What are the symptoms of Hashimoto’s Disease? 

Hashimoto’s disease is a condition in which your immune system attacks your thyroid, a small gland at the base of the neck (below Adam’s apple). The thyroid gland is part of your endocrine system, which produces hormones that coordinate many of your body’s functions.

Inflammation from Hashimoto’s disease, also known as Chronic Lymphocytic Thyroiditis, often leads to an underactive thyroid gland (hypothyroidism). Hashimoto’s disease is the most common cause of hypothyroidism.

Signs and symptoms of hypothyroidism include:

  • Fatigue and sluggishness
  • Increased sensitivity to cold
  • Constipation
  • Pale, dry skin
  • A puffy face
  • Brittle nails
  • Hair loss
  • Enlargement of the tongue
  • Unexplained weight gain
  • Muscle aches, tenderness, and stiffness
  • Joint pain and stiffness
  • Muscle weakness
  • Excessive or prolonged menstrual bleeding 
  • Depression
  • Memory lapses 4

There are cases in which Hashimoto’s disease does not produce any noticeable symptoms. The condition may be discovered during investigations for other, perhaps unrelated, medical problems.

How can MTHFR cause Hashimoto’s Disease?

The MTHFR enzyme is crucial for your body to methylate properly. When it does not, you’re at risk for developing a number of diseases including autoimmunity and thyroid dysfunction. 5

When the MTHFR genes work properly, you can more efficiently make proteins, use antioxidants, metabolize hormones, enjoy more stable brain chemistry, better eliminate toxins and heavy metals, and manage inflammation. All of these functions are vital to managing Hashimoto’s hypothyroidism.

In certain cases of Hashimoto’s hypothyroidism, the sufferer can develop a sluggish MTHFR enzyme.

This happens because thyroxine (T4) helps produce the body’s most active form of vitamin B2, flavin adenine dinucleotide (FAD).

Vitamin B2 must be converted into active FAD by T4 so that the body can use it. The MTHFR enzyme must have enough FAD in order to do its job. If FAD levels are low due to too little T4, then the MTHFR enzyme slows down. This then leads to low methylfolate, and in turn, to low neurotransmitters and low SAMe (S-Adenosyl methionine).

Glutathione, methylation and folate are associated with MTHFR function and thyroid-related conditions. Glutathione is the most abundant detoxifier in the body. It keeps inflammation low, protecting you against disease.

Having lower glutathione levels, people with MTHFR mutations are more vulnerable to stress, toxins, and illness. Research shows a direct correlation between a breakdown in the glutathione system and autoimmune disease, such as Hashimoto’s disease.

Autoimmune disease is linked to leaky gut, yet in order to have a healthy gut, maintenance of glutathione levels is necessary. 

Essential vitamins in the methylation process to ensure healthy Thyroid function


Folate, B6, B12, and riboflavin are important vitamin factors in the methylation process.


Folic acid is the synthetic form of folate used to fortify foods, yet it requires MTHFR for the conversion to a useable form. Without MTHFR, folic acid can accumulate, docking to folate receptor sites making the methylfolate in your body unable to be utilised.  It can also result in issues with the bioavailability of B12, potentially causing;

  • Masking a B12 deficiency – as a result, consequences of low B12 (energy, nerve, and brain functions) continue to go untreated and cause anaemia
  • B12 deficiency is found in approximately 40% of hypothyroid patients
  • Low B12 also means an accumulation of homocysteine (an amino acid that needs B12 to convert it to methionine). 
  • Homocysteine is a marker for inflammation such that high levels are associated with a high risk of disease, i.e. thyroid disorders and cardiovascular disease. 
  • Impaired methylation and high homocysteine negatively affect the production of glutathione – inflammation and oxidative stress are increased under these conditions


Riboflavin (vitamin B2) is a factor in the conversion of MTHFR. First, the body must convert riboflavin to its useable form, FAD, and the thyroid hormone thyroxine is necessary for this to occur.

How Thyroxine function plays an important role

Thyroxine (T4) is the hormone the thyroid releases into the bloodstream, where it travels to organs such as the liver and kidneys. The hormone then converts to its active form, T3, which is used by the cells. 

Thyroxine has important roles in digestion, brain, heart, muscle and bone health, making it one of the most important hormones we have. The body is designed to tightly regulate levels of thyroxine in the bloodstream. 

However, it often becomes derailed and conditions such as hyperthyroidism or hypothyroidism can result. When thyroxine is low, less is available to convert riboflavin, to a form needed for MTHFR. Therefore, folate metabolism, methylation, and everything within its sphere of influence are affected.

Should defective MTHFR functioning exist due to a genetic mutation, the consequences may be exaggerated further. 6

A recent study demonstrates that the prevalence of MTFHR mutations among patients with autoimmune thyroid disease is increasing. 7

This correlation enables Functional Medicine Practitioners to understand the root cause of Hashimoto’s disease and find treatment that will work for the individual.

How you can help to support your thyroid function

  • Ensure you are getting the appropriate thyroid medication
  • Have some TFT blood tests –
    • Thyroid function tests are used to check for a number of thyroid problems
    • The tests usually include thyroid-stimulating hormone (TSH), T4, and T3
    • Other tests on the thyroid include various antibodies related to thyroid tissue including TPO and TG antibodies
  • As part of your blood tests, get your Functional Medicine health practitioner to perform some MTHFR tests
  • Minimize exposure to chemicals in food as well as in your external environment
  • Get some sun –
    • Sun exposure has been shown to be protective against autoimmune disease
    • Low levels of Vitamin D impact the thyroid gland
    • Vitamin D should be tested in the blood.
  • Support detoxification with a tailored nutrition plan and prescribed supplements
  • Replace synthetic folic acid supplements and processed foods fortified with folic acid with L-methylfolate or 5-MTHF
  • Include foods with naturally occurring folate in your diet –
    • Asparagus, broccoli, peaches, avocado, spinach, garlic, squash, grapefruit, cauliflower, and cabbage
  • Optimize your gut health 
  • Manage stress –
    • chronic stress impairs thyroid function at many different levels

How we can help

If you have an autoimmune condition, particularly Hashimoto’s, Graves’ or thyroid dysfunction, it’s important to understand your MTHFR status.

If you are struggling with thyroid problems or suspect MTHFR is affecting you, our team at our Advanced Functional Medicine clinic can support you by conducting MTHFR testing as part of your blood work. We will then find the best way to assist your thyroid condition.

If you would like more information on how to start the process of testing or to find out more, please contact us at 1800 11 22 36 or complete the form below.

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The above information is intended to be general, educational advice only, on topics which are of interest to us. It is not intended to represent specific or individual health or medical advice and is not specific to your situation. The below information is educative and is not intended to advertise any service.

Before making any decisions in relation to your health, you should always discuss your individual situation with your own health practitioners to ensure that any advice you have read is right for you.

Jarrod Cooper – ND

Jarrod Cooper – ND

Jarrod Cooper - ND is the founder of Advanced Functional Medicine Australia. He is a Naturopathic Doctor with extensive functional medicine training from leading practitioners in the USA and worldwide.

He is leading the way with advancements of functional medicine, clinically implementing worldwide best practices in Functional Medicine throughout Australia.

Jarrod consults in person from Perth, Western Australia and also online via Telehealth throughout Australia and worldwide.

If you are looking for personalised treatment, we highly recommend contacting Jarrod Cooper’s Advanced Functional Medicine clinic in Australia.

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