HSA | FSA CARDS ARE NOW ACCEPTED

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Understanding Your BHMT Gene and What It Means for Methylation and Health

The BHMT gene makes an enzyme called betaine-homocysteine methyltransferase. This enzyme helps convert homocysteine into methionine using betaine, a compound made from choline. This reaction is a key part of the methylation cycle, which supports DNA repair, detoxification, neurotransmitter production, and healthy homocysteine levels. Most BHMT activity happens in the liver and kidneys.

Variations in BHMT activity can change how well your body uses choline and manages methylation. When BHMT activity is reduced, the body may rely more heavily on other pathways for methylation, and homocysteine levels can rise. That may affect heart health, pregnancy outcomes, and overall metabolic balance. Environmental stress, oxidative damage, and diets very high in methionine can strain this pathway.

How to Read This Result

This report focuses on one common BHMT variant, rs3733890. Your genotype for this variant can be AA, AG, or GG. Below you will find an explanation of what each genotype typically means for BHMT function, and practical steps you can take to support methylation and homocysteine balance through diet, supplements, and lifestyle.

AA — Two effect alleles (reduced BHMT activity)

What this means

  • This genotype is associated with reduced BHMT enzyme activity.
  • Conversion of homocysteine to methionine via betaine is decreased, which can lead to higher homocysteine and less efficient methylation.
  • There may be an increased risk for cardiovascular issues or complications where methylation is important, especially if dietary methyl donor intake is low.

Diet recommendations

  • Increase choline-rich foods: eggs (especially yolks), beef liver (if tolerated), chicken, fish, and soy products.
  • Include betaine sources: beets, spinach, quinoa, wheat bran, and shellfish.
  • Support folate status with leafy greens, asparagus, Brussels sprouts, and legumes. Consider food forms of folate first.
  • Ensure adequate vitamin B12 from animal products or fortified foods; vegetarians and older adults may need a supplement.
  • Balance protein intake — avoid excessive methionine-rich diets without balancing methyl donors.

Supplement recommendations (consider under provider guidance)

  • Trimethylglycine (TMG / betaine) to directly support BHMT-mediated methylation when dietary betaine is inadequate.
  • Methylfolate and methylcobalamin if testing or symptoms suggest low folate or B12; take only with medical advice.
  • Zinc and magnesium to support enzyme function and methylation reactions.
  • Phosphatidylcholine or choline supplements if dietary intake is low.

Lifestyle and monitoring

  • Reduce oxidative stress with antioxidant-rich foods (berries, colorful vegetables, green tea) and by avoiding excessive alcohol and smoking.
  • Manage stress and sleep, since chronic stress can affect methylation and metabolic balance.
  • Regular exercise supports cardiovascular health and metabolic regulation.
  • Ask your healthcare provider about checking fasting homocysteine and B-vitamin levels if you have cardiovascular risk factors, a family history, or pregnancy planning concerns.
AG — One effect allele (intermediate BHMT activity)

What this means

  • This genotype generally yields intermediate BHMT activity compared to AA and GG.
  • Conversion of homocysteine to methionine via betaine may be somewhat reduced, but often the effect depends on diet and nutrient availability.
  • With adequate methyl donor intake, most people with AG will maintain healthy methylation and homocysteine levels.

Diet recommendations

  • Eat a balanced diet with regular sources of choline: eggs, fish, poultry, and legumes.
  • Include betaine-containing foods such as beets and spinach a few times per week.
  • Keep folate-rich vegetables and B12-containing foods in your routine, especially if you are pregnant or planning pregnancy.

Supplement recommendations (consider under provider guidance)

  • Consider a general B-complex that includes folate and B12 if your diet is limited or you have elevated homocysteine.
  • Choline or phosphatidylcholine supplements can be useful if dietary intake is low.

Lifestyle and monitoring

  • Maintain a heart-healthy lifestyle: avoid smoking, limit alcohol, exercise regularly, and manage weight.
  • Monitor stress and prioritize sleep to support metabolic resilience.
  • Consider periodic homocysteine testing if you have other risk factors for cardiovascular disease or pregnancy-related concerns.
GG — Zero effect alleles (typical BHMT activity)

What this means

  • This genotype is associated with normal BHMT enzyme activity and typical conversion of homocysteine to methionine via betaine.
  • With sufficient dietary methyl donors, your methylation cycle is expected to function well, supporting detoxification, DNA repair, and neurotransmitter balance.

Diet recommendations

  • Continue a varied diet with regular sources of choline, folate, and B12.
  • Include whole grains, vegetables, and legumes to support overall methylation and cardiovascular health.

Supplement recommendations (if needed)

  • Most people with GG do not require targeted BHMT support unless testing shows elevated homocysteine or dietary intake is very low.
  • General multivitamins or a balanced B-complex can help if diet is inconsistent.

Lifestyle and monitoring

  • Maintain healthy habits: balanced diet, regular exercise, good sleep, and stress management.
  • Routine preventive care and periodic bloodwork as recommended by your healthcare provider will help catch changes early.

When to Talk to Your Healthcare Provider

Consider discussing your BHMT result with your healthcare provider if you have high homocysteine, a personal or family history of cardiovascular disease, difficulties with fertility or pregnancy, or symptoms that suggest impaired methylation such as unexplained fatigue, mood changes, or difficulty detoxifying. Your provider can help interpret this result alongside blood tests, medication history, and other genetic or health information.

Practical Next Steps

  • Review your diet for choline, betaine, folate, and B12 sources and make incremental changes to include whole-food sources.
  • Talk to your provider about measuring fasting homocysteine, serum folate, and B12 if you have risk factors.
  • If considering supplements, discuss options like TMG, methylfolate, methylcobalamin, or choline with your provider to choose safe doses and avoid interactions.
  • Adopt lifestyle habits that support methylation: reduce alcohol and smoking, prioritize sleep, manage stress, and include regular physical activity.

PlexusDx provides genetic education to help you understand potential predispositions and actionable lifestyle choices. This information is educational only and is not medical advice. Always consult your healthcare provider before making changes to diet, supplements, or medications based on genetic results.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About Methionine Cycle and BHMT rs3733890

What does the BHMT rs3733890 variant affect in my methylation cycle?

The BHMT gene helps convert homocysteine into methionine using betaine (made from choline). Your rs3733890 genotype (AA, AG, or GG) can influence how efficiently this step in the methylation cycle works, which may affect DNA repair, detoxification, neurotransmitter production, and homocysteine levels.

How do AA, AG, and GG genotypes typically differ for homocysteine and heart health?

AA is associated with reduced BHMT activity, which can decrease conversion of homocysteine to methionine and may increase the likelihood of higher homocysteine and cardiovascular risk—especially when methyl-donor intake is low. AG is typically intermediate activity, and many people maintain healthy homocysteine when diet provides enough methyl donors. GG is associated with typical BHMT activity, supporting methylation and homocysteine balance when choline, folate, and B12 intake is adequate.

What diet and supplement steps can support BHMT function based on my results?

Across genotypes, prioritize food sources of choline (e.g., eggs, fish, poultry, soy), betaine (e.g., beets, spinach, quinoa, wheat bran, shellfish), folate (leafy greens, asparagus, Brussels sprouts, legumes), and B12 (animal foods or fortified options). If you have AA or suspected low folate/B12 or elevated homocysteine, options often discussed with a provider include TMG/betaine, methylfolate, methylcobalamin, zinc, magnesium, and possibly choline/phosphatidylcholine when intake is low. Consider checking fasting homocysteine and B-vitamin levels with your healthcare provider if you have cardiovascular risk factors, pregnancy planning concerns, or fertility challenges.

What tests can help me learn more about Methionine Cycle and BHMT rs3733890?

The Genetic Methylation Test delivers over 300 genetic insights related to methylation, detoxification, and nutrient processing. The Methylation Pathway Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.