Having two copies of the MTHFR gene mutation may raise your risk for certain health conditions, though more research is needed. You may have the mutation and not find out unless you undergo genetic testing or have a health issue.

The abbreviation MTHFR refers to a relatively common genetic mutation. It stands for methylenetetrahydrofolate reductase, and having this mutation may lead to high levels of homocysteine in the blood and low levels of folate and other vitamins.

Its main function is to provide your body with instructions for creating the MTHFR protein, which helps your body produce folate. This B vitamin is necessary to create DNA.

You can have either one or two mutations — or neither — on the MTHFR gene. These mutations are often called variants. A variant is a part of a gene’s DNA that’s commonly different or varies from person to person.

Having one variant (heterozygous) is less likely to contribute to health issues. Some experts believe that having two mutations (homozygous) may lead to more serious problems.

There are two variants, or forms, of mutations that can occur on the MTHFR gene. The specific variants are:

  • C677T: About 38% of subjects in a 2020 study were found to have a mutation at gene position C677T.
  • A1298C: Limited research exists regarding this variant, which was found in about 40% of the subjects.

It’s also possible to acquire both C677T and A1298C mutations, which is one copy of each.

Gene mutations are inherited, which means you acquire them from your parents. At conception, you receive one copy of the MTHFR gene from each parent. If both have mutations, your risk of having a homozygous mutation is higher.

However, in cases where a person holds two copies of the C677T mutation or one copy of each mutation, they may be at risk of high homocysteine (an amino acid) levels, which may affect the body’s function.

Health conditions linked to MTHFR depend on your type of mutation and how many copies you contain.

If you have only one copy of the C677T or A1298C mutation or two copies of the A1298C mutation, there are typically no health conditions or risks linked.

Conditions that may be associated with MTHFR include:

A person with two gene variants or who is homozygous for the MTHFR mutation may have an increased chance of health conditions.

MTHFR isn’t an issue unless you have very high homocysteine levels or other health symptoms.

Still, you might be curious to discover your individual MTHFR status. Consider visiting your doctor and discussing the pros and cons of being tested.

Keep in mind that genetic testing may not be covered by your insurance. Call your insurance provider if you’re considering getting tested to ask about costs.

At-home genetic testing kits also offer screening for MTHFR. The customer’s DNA is collected from the inside of the cheek with a sterile cotton swab. The test screens for two of the most common MTHFR mutations. Results are provided 5-6 business days after your sample is received.

A 2019 study examined 246 women who had experienced recurrent miscarriages and held the C677T MTHFR gene mutation. While the mutation was linked to these miscarriages, results found that administering folic acid alongside low dose aspirin and enoxaparin was a helpful therapy in helping prevent recurrent miscarriages.

Speak with your doctor about testing if any of the following situations apply to you:

  • You’ve experienced several unexplained miscarriages.
  • You’ve had a child with a neural tube defect.
  • You know that you have the MTHFR mutation, and you’re pregnant.

Though there’s little evidence to support it, some doctors suggest taking blood-thinning medications and extra folate supplementation.

Having an MTHFR variant doesn’t mean that you need medical treatment. It could just mean you need to take a vitamin B supplement.

High homocysteine levels

Treatment is typically required when you have very high homocysteine levels, almost always above the level attributed to most MTHFR variants. Your doctor should rule out other possible causes of increased homocysteine, which can occur with or without MTHFR variants.

From there, the treatment will depend on the cause and doesn’t necessarily take into account MTHFR. The exception is when you’ve been diagnosed with all of the following conditions at the same time:

  • high homocysteine levels
  • a confirmed MTHFR mutation
  • vitamin deficiencies in folate, choline, or vitamins B12, B6, or riboflavin

In these cases, your doctor may suggest supplementation to address deficiencies along with medications or treatments to address the specific health condition.

People with MTHFR mutations may also wish to take preventive measures to lower their homocysteine levels. One preventive measure is changing certain lifestyle choices, which may help without the use of medications. Examples include:

Potential supplementation

The MTHFR gene mutation inhibits the body’s processing of folic acid and other important B vitamins. Countering its effects, changing the supplementation of this nutrient is a potential focus.

Folic acid is actually a human-made version of folate, a naturally occurring nutrient found in foods. Taking the bioavailable form of folate — methylated folate — may help your body absorb it more readily.

Most people are encouraged to take a multivitamin that contains at least 0.4 milligrams (mg) of folic acid each day.

Pregnant people are not encouraged to switch prenatal vitamins or care based on their MTHFR status alone. This means taking the standard dose of 0.6 mg of folic acid daily.

People with a history of neural tube defects should speak with their doctor for specific recommendations.

Speak with your doctor before changing vitamins and supplements. Some may interfere with other medications or treatments you’re receiving.

Your doctor may also suggest prescription vitamins that contain folate instead of folic acid. Depending on your insurance, the costs of these options may vary compared to over-the-counter varieties.

What foods should you avoid if you have MTHFR?

Eating foods rich in folate may help naturally support your levels of this important vitamin. However, supplementation may still be necessary.

People with known MTHFR mutations should discuss their nutrition plan in detail, along with any potential supplementation or medical treatments, with a healthcare professional.

It should be emphasized that, contrary to what was previously thought, people with MTHFR variants can process all forms of folate, including folic acid. In fact, folic acid is the only type of folate that has been shown to help prevent neural tube defects.

Be sure to check labels, as this vitamin is added to many enriched grains, like pasta, cereals, breads, and commercially produced flours.

Your MTHFR status may or may not be affecting your health. More research is needed to determine the true impact, if any, associated with the variants.

Again, many respected health organizations don’t recommend testing for this mutation, especially without other medical indications. Speak with your doctor about the benefits and risks of testing, as well as any other concerns you may have.

Continue to eat well, exercise, and practice other healthy lifestyle habits to support your overall well-being.