Thyroid Thursday Episode 62: Hypothyroidism and MTHFR
I’ve had many people come to my office for support with Hypothyroidism who have found out they have a gene polymorphism of the MTHFR gene and want to know if there is a connection and what to do about it.
The first thing I need to review is what MTHFR is. MTHFR refers to a gene and the enzyme it produces called methylenetetrahydrofolate reductase. This enzyme is responsible for the conversion of dietary folate to the more active form used by the body, methylenetetrahydrofolate (MTHF).
MTHF is used in the cells of the body for many functions. One of the major processes that utilizes MTHF is a process called methylation. Methylation is involved in about 200 different reactions in the cells including; energy production, neurotransmitter production and metabolism, cell membranes, bile formation, detoxification, glutathione production, and many more.
It’s thought that approximately 50% of the US population has an alteration from the normal or “wild” form of the gene. The variation of the amino acid sequence changes the function of the enzyme produced. The variation from the wild type is call a polymorphism or snp.
We have thousand of genes in the body and many of them have these alteration or polymorphisms. Some have no impact on the function of the enzymes produced, some have significant consequences. Alterations in the MTHFR gene can be mild or insignificant for some and devastating for others.
Polymorphism in the MTHFR gene are typically associated with reduced activity of the enzyme produced.
For the MTHFR enzyme to work properly it requires cofactors. Cofactors are vitamins, mineral, or other molecules that are needed for the enzyme to work. If you’re confused, let’s use the analogy of your car. Your car can get you from point A to point B. But for the car to work it needs oil and gas. Oil and gas would be considered cofactors needed to make the car work.
One of the cofactors needed for MTHFR to work is vitamin B2, also known as Riboflavin. When we eat food, or take vitamins with riboflavin, the riboflavin is absorbed into the body and transported into the cells. Once inside the cells, riboflavin must be converted into an active form to support MTHFR in the cells. The active form of riboflavin is called Flavin Adenine Dinucleotide. We will just use the acronym FAD.
The conversion of riboflavin to FAD requires its own enzyme and cofactors. The enzyme is called Riboflavin Kinase (also known as Flavokinase) and its cofactor is the thyroid hormone triiodothyronine (T3).
Here is where we get to the good stuff.
As I’ve explained in multiple videos, hypothyroid symptoms are the result of reduced levels of T3 reaching the nucleus of the cells, a condition we call Cellular hypothyroidism. And as you may remember, cellular hypothyroidism can occur with a healthy thyroid gland and normal lab ranges of serum T4 and T3.
In cases of cellular hypothyroidism, there can be a reduced amount of thyroid hormone reaching the cell or in many cases the cell is deactivating T4 and T3 due to some cellular stress response or a need to slow down cell metabolism. T4 is converted to reverse T3 (rT3), and T3 is converted into T2. Both are inactive forms.
If there is reduced T3 inside your cells, then riboflavin conversion to FAD goes down. If there is less FAD available for the MTHFR enzyme, than you will have reduced function of the enzyme and less MTHF produced. This compromises all the functions I listed above.
If you have cellular hypothyroidism for any reason, FAD production is reduced, MTHFR function is reduced regardless of which variant of MTHFR you have. If you have a MTHFR polymorphism MTHFR677 or MTHFR1298 that already have reduced function, the cellular hypothyroidism will compound the problem and have significant impact on your cell physiology and your health.
So, what can you do? Should you take more riboflavin? Eat more foods with riboflavin? Take more thyroid hormone?
The answer is not that simple. But, you could look at the foods you are eating. If you aren’t taking foods high in riboflavin, that’s a start. More likely if you have hypothyroid symptoms you will need to address the cause of your cellular hypothyroidism to fix the problem.
If you remember from past episodes this usually means addressing cellular stress. When there is chronic stress on the body cellular thyroid physiology is often down regulated increasing the conversion of T4 and T3 to inactive forms. The stress can come from organisms, heavy metals, organic chemicals, emotional stress, reduced sleep, compromised breathing, poor diets, and other lifestyle factors.
I’ve talked about the things you can do on your own in previous videos to address cellular hypothyroidism. If you haven’t done those things yet, get started. If you have and you haven’t had success, or you just want some help, just call my office and schedule a thyroid consultation.
