NAH on Facebook NAH on Twitter

Thyroid Disease and MTHFR: How a Gene Mutation Can Affect Thyroid Function

Thyroid Disease and MTHFR: How a Gene Mutation Can Affect Thyroid Function

Genes are bundles of information that are passed down through parents to their offspring. Numerous attributes such as eye and hair color, height, and skin tone are determined by our genes. Recent research suggests that genes may even influence the likelihood of developing thyroid issues. Specifically, it is posited that defective methylenetetrahydrofolate (MTHFR) genes may contribute to the occurrence of thyroid disease.

To better understand this connection, we must first discuss the role of MTHFR, the possible complications that come with MTHFR mutation, and the specific effects of irregular MTHFR on thyroid activity.

The Role of MTHFR

The MTHFR gene is responsible for producing an enzyme called methylenetetrahydrofolate reductase. This enzyme has multiple functions such as facilitating the conversion of folic acid, also called folate, into methylfolate.

Methylfolate plays an essential role in the production of neurotransmitters such as serotonin, dopamine, and norepinephrine. Each of these communicative compounds are recognized for their ability to influence mood and regulate a wide range of bodily processes.

Methylfolate is also involved in the creation of s-adenosylmethionine (SAMe), which is used in the regulation of over 200 enzymes throughout the body. The MTHFR enzyme may also be used in conjunction with folate to break down an amino acid named homocysteine to produce methionine. Both methylfolate and methionine are used in a number of important bodily processes.

As a key component for the production of methylfolate and methionine, the MTHFR gene indirectly affects several areas of wellness. These include:

  • Cell maintenance and repair
  • Metabolization of chemicals, toxins, B-vitamins, neurotransmitters, and hormones
  • Production of the body’s main antioxidant, glutathione
  • Regulation and production of various neurotransmitters
  • Supporting protein and DNA functionality
  • Synthesis of CoQ10, creatine, melatonin, carnitine, and phosphatidylcholine; all of which are used in critical bodily processes including immunity and energy regulation

Clearly, by influencing so many essential functions, MTHFR reductase and by extension the MTHFR gene are important factors of wellness. As such, it should not come as a surprise that any sort of mutation or irregularity of the MTHFR gene may result in notable dysfunction.

Inherited Irregularities

Like all genes, the make-up of MTHFR is highly dependent on the genes passed on by the parents. For example, one person may inherit perfectly functional MTHFR genes while another could be born with irregular MTHFR genes in the form of MTHFR SNPs (single nucleotide polymorphisms). This specific type of irregularity can reduce MTHFR gene functionality by up to 70 percent. Unfortunately, being born with regular or irregular MTHFR genes is left to chance as methods for gene alteration are currently in infancy.

The Dangers of MTHFR Defects

MTHFR variations result in a decrease in methylation, which can lead to a wide array of health issues. In fact, MTHFR specialist Dr. Ben Lynch has identified more than 60 conditions associated specifically with MTHFR SNPs. Other experts support Lynch’s findings and suggest that MTHFR mutations may be connected to a collection of serious health issues relating to the heart, eyes, brain, thyroid, immune function, and more. Additionally, it is strongly believed that MTHFR mutation may predispose individuals to cancers, birth defects, and autoimmune disorders.

Specific conditions associated with MTHFR mutation include:

  • Thrombosis
  • Microalbuminuria
  • Atherosclerosis
  • Alzheimer’s disease
  • Ectopia lentis
  • Bone fractures
  • Alopecia areata
  • Anencephaly
  • Homocystinuria
  • Presbycusis
  • Spina bifida
  • Heart disease
  • Stroke
  • Hypertension
  • Preeclampsia
  • Glaucoma
  • Celft palate

MTHFR and the Thyroid

In addition to the issues mentioned above, recent research suggests that MTHFR mutations may also influence thyroid activity and encourage the development of thyroid disease through multiple mechanisms.

Glutathione is the body’s primary antioxidant and detoxifier. Its responsibilities include regulating inflammation, combating illness, and protecting important bodily processes. Studies show that a lack of glutathione is associated with greater toxicity, immune stress, and autoimmune disease such as Hashimoto’s thyroiditis; a leading cause of hypothyroidism.

Those with MTHFR defects may be unable to efficiently produce glutathione. The decline of glutathione production tied to MTHFR mutation may result in a deficit thereby increasing the risk of systemic dysfunction and thyroid disease.

Homocysteine is an amino acid that may act as a marker for various conditions. For example, elevated levels of homocysteine may be indicative of inflammation, cardiovascular disease, and thyroid disorders. Normally, the body regulates homocysteine levels by breaking it down with the assistance of vitamin B12. However, MTHFR defects can cause poor B12 values resulting in homocysteine buildup. This impedes glutathione production and activity thereby promoting oxidative stress, inflammation, and the occurrence of autoimmune thyroid disease. 

Interestingly, thyroid disease may also inhibit functions of MTHFR including folate metabolism and methylation, which can lead to a further worsening of thyroid function.

Low values of thyroid hormone can impede conversion of riboflavin (B2) into a cofactor of MTHFR called flavin adenine dinucleotide (FAD). To function properly, MTHFR must have a healthy supply of FAD. Thyroid disease, specifically hypothyroidism, can impede FAD production and subsequently reduce MTHFR activity. This interaction of reduced thyroid function and limited MTHFR activity creates a cycle of decline that can lead to a continual worsening of thyroid activity and overall bodily function.

Finding the Link Between Genes and the Thyroid

Genes are the source code for virtually every part of who we are. Unsurprisingly, even minor irregularities or mutations in our genes can have a significant impact. One gene that has shown to have an unexpected effect on thyroid health is the MTHFR gene. Further research is required to confirm the influence of MTHFR defects on the thyroid. However, multiple studies suggest a relationship between MTHFR mutation and the occurrence of thyroid disease.

Being aware of a possible genetic predisposition to thyroid disease may help patients better prepare, react to, or treat an existing or future thyroid condition.

If you are suffering from thyroid-related dysfunction, be sure to consider the possibility of gene defects and speak with a doctor about potential treatment options.


1. Kvaratskhelia T, Kvaratskhelia E, Kankava K, Abzianidze E. “MTHFR GENE C677T POLYMORPHISM AND LEVELS OF DNA METHYLTRASFERASES IN SUBCLINICAL HYPOTHYROIDISM.” Georgian Med News. 2017 Apr 19-24.
2. Bamashmoos, S. Al-Nuzaily, M. “Relationship between total homocysteine, total cholesterol and creatinine levels in overt hypothyroid patients.” Springerplus. 2013; 2: 423.
3. Ben Lynch. “MTHFR Mutation. MTHFR and the Conditions they cause.”
4. Ben Lynch. “MTHFR Mutation. MTHFR and Thyroid Conditions.”
5. Bicíková M, Hampl R, Hill M, et al. “Steroids, sex hormone-binding globulin, homocysteine, selected hormones and markers of lipid and carbohydrate metabolism in patients with severe hypothyroidism and their changes following thyroid hormone supplementation.” Clin Chem Lab Med. 2003 Mar;41(3):284-92.
6. Catargi B, Parrot-Roulaud F. “Homocysteine, hypothyroidism, and effect of thyroid hormone replacement.” Thyroid. 1999 Dec;9(12):1163-6.
7. Jabbar, A. Yawar, A. “Vitamin B12 deficiency common in primary hypothyroidism.” J Pak Med Assoc. 2008 May;58(5):258-61.