Methylenetetrahydrofolate Reductase (MTHFR) Deficiency
What is Methylenetetrahydrofolate Reductase (MTHFR) Deficiency?
MTHFR deficiency is a genetic condition that affects how your body processes folate, also known as vitamin B9. The MTHFR enzyme converts folate into its active form, which your body needs to turn homocysteine into methionine. Methionine is an essential amino acid that helps build proteins and supports important body functions.
When MTHFR enzyme activity is reduced, homocysteine levels can build up in your blood. This happens because your body cannot process it efficiently. Two common genetic variants, C677T and A1298C, cause most cases of reduced MTHFR function. These genetic changes are inherited from your parents.
Many people carry one or two copies of MTHFR variants and never know it. The condition ranges from mild to severe depending on which variants you have. Elevated homocysteine can increase risks for cardiovascular issues, pregnancy complications, and other health concerns. Understanding your MTHFR status helps you make informed choices about nutrition and lifestyle.
Symptoms
- Elevated homocysteine levels on blood tests
- Fatigue and low energy
- Difficulty concentrating or brain fog
- Mood changes including anxiety or depression
- Numbness or tingling in hands and feet
- Weakness or muscle pain
- Headaches or migraines
- Pregnancy complications including recurrent miscarriage
- Blood clots in some cases
- Cardiovascular symptoms in severe cases
Many people with MTHFR variants have no symptoms at all. The condition often goes undetected until routine blood work shows elevated homocysteine. Some people only notice symptoms when they are under stress or not getting enough folate in their diet.
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Causes and risk factors
MTHFR deficiency is caused by genetic variants inherited from one or both parents. The C677T and A1298C variants are the most common types. If you inherit one variant copy, you have a heterozygous mutation with mild effects. If you inherit two copies of the same variant, you have a homozygous mutation with more significant enzyme reduction. Your ethnicity can affect your risk, with C677T variants more common in Hispanic and Mediterranean populations.
Risk factors include family history of MTHFR variants, elevated homocysteine, cardiovascular disease at young ages, or pregnancy complications. Low folate intake makes symptoms worse because your body has less raw material to work with. Certain medications like methotrexate can further reduce folate levels. Stress, alcohol use, and digestive issues that impair nutrient absorption can also worsen the condition.
How it's diagnosed
MTHFR deficiency is typically diagnosed by measuring homocysteine levels in your blood. Elevated homocysteine suggests your body is not processing folate efficiently. Genetic testing can identify specific MTHFR variants like C677T and A1298C. However, homocysteine testing is often the first step because it shows how the variants are actually affecting your body.
Rite Aid offers homocysteine testing as an add-on to our flagship health panel. Testing through Quest Diagnostics locations makes it easy to check your levels. Your doctor may also test vitamin B12, folate, and B6 levels to get a fuller picture of your methylation status. These tests help determine if dietary changes or supplements could help lower your homocysteine.
Treatment options
- Increase dietary folate from leafy greens, legumes, citrus fruits, and fortified grains
- Take methylfolate supplements, the active form of folate your body can use directly
- Ensure adequate vitamin B12 intake through food or methylcobalamin supplements
- Add vitamin B6 to support homocysteine metabolism
- Reduce alcohol consumption to preserve folate levels
- Manage stress through regular exercise, sleep, and relaxation practices
- Avoid smoking, which raises homocysteine levels
- Work with a functional medicine doctor or nutritionist for personalized guidance
- Monitor homocysteine levels regularly to track progress
- Discuss medication adjustments with your doctor if you take drugs that affect folate
Need testing for Methylenetetrahydrofolate Reductase (MTHFR) Deficiency? Add it to your panel.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
MTHFR deficiency is a genetic condition that reduces your body's ability to process folate into its active form. This leads to buildup of homocysteine in your blood. The condition is caused by inherited variants in the MTHFR gene, most commonly C677T and A1298C.
Symptoms include fatigue, brain fog, mood changes, numbness or tingling, and headaches. Some people experience pregnancy complications or cardiovascular symptoms. However, many people with MTHFR variants have no symptoms and only discover the condition through blood testing.
Doctors typically measure homocysteine levels in your blood as the first step. Elevated homocysteine suggests reduced MTHFR enzyme function. Genetic testing can identify specific MTHFR variants, but homocysteine testing shows how the variants actually affect your body.
Yes, Rite Aid offers homocysteine testing as an add-on to our health panel. This blood test measures how well your body processes folate and homocysteine. Testing is available at Quest Diagnostics locations nationwide.
MTHFR genetic variants are a common cause of elevated homocysteine. Low folate, vitamin B12, or B6 levels can also raise homocysteine. Other factors include kidney disease, certain medications, smoking, and excessive alcohol consumption.
Treatment focuses on lowering homocysteine through diet and supplements. Taking methylfolate, the active form of folate, helps bypass the MTHFR enzyme problem. Vitamins B12 and B6 also support healthy homocysteine metabolism. Lifestyle changes like reducing alcohol and managing stress are important too.
Eat plenty of folate-rich foods like leafy greens, lentils, beans, asparagus, and citrus fruits. Include B12 sources like eggs, fish, meat, and fortified foods. Foods high in B6 like chicken, salmon, potatoes, and bananas also help. Focus on whole foods rather than processed items.
Severity depends on which variants you have and how elevated your homocysteine levels are. High homocysteine increases risk for cardiovascular disease, blood clots, and pregnancy complications. However, most people with MTHFR variants manage the condition well through diet, supplements, and lifestyle changes.
Many doctors recommend methylfolate instead of regular folic acid for people with MTHFR variants. Methylfolate is the active form your body can use directly without needing the MTHFR enzyme. Regular folic acid requires conversion, which MTHFR variants make difficult.
Yes, MTHFR variants can increase risk of pregnancy complications including recurrent miscarriage and neural tube defects. Elevated homocysteine may affect placental development. Women with MTHFR variants should work closely with their doctor and take methylfolate before and during pregnancy.