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Methionine, Choline, and Your Methylation Pathway: What Your Genotype May Mean

Methionine is an essential amino acid and the starting point for the body’s methylation pathway. After you eat methionine it becomes S-adenosylmethionine (SAMe), the body’s universal methyl donor used for DNA methylation, neurotransmitter synthesis, lipid metabolism, and detoxification. Once SAMe donates a methyl group it becomes homocysteine, which must either be remethylated back to methionine or diverted into the transsulfuration pathway to form cysteine and glutathione.

One route of methionine use is converting it into phosphatidylcholine, a major choline-containing phospholipid important for cell membranes, liver lipid transport, and acetylcholine production. Some genetic differences can make that conversion less efficient, increasing reliance on dietary choline and shifting how SAMe and homocysteine are used. Below are practical, easy-to-follow interpretations and lifestyle suggestions based on rs10791957 genotype.

Clinical and practical considerations

  • Choline supports liver health, cell membrane integrity, lipid transport, and neurotransmitter production.
  • When endogenous choline production from methionine is reduced, dietary choline becomes more important to avoid fatty liver and support methylation balance.
  • Support methylation overall by ensuring adequate B vitamins, especially folate and vitamin B12, which help remethylate homocysteine.
  • Consider blood testing if clinically indicated: fasting homocysteine, liver enzymes, and nutrient status (serum B12, RBC folate, and possibly plasma choline) can help guide care with your clinician.

Diet, supplements, and lifestyle suggestions

  • Eat choline-rich foods regularly: eggs, liver, soy products, fish, and some legumes. One large egg is a very concentrated source of choline.
  • Maintain adequate protein to supply methionine, but avoid excessive methionine-only supplements without clinical supervision because high SAMe can shift metabolism toward transsulfuration.
  • Ensure sufficient B vitamins: folate (preferably natural food folate or methylfolate if recommended), vitamin B12, B6, and riboflavin support methylation and homocysteine clearance.
  • Consider a choline supplement if dietary intake is low: phosphatidylcholine or choline bitartrate are common forms. Discuss dose with your healthcare provider.
  • Support antioxidant pathways with a diet high in fruits, vegetables, and sulfur-containing vegetables (onions, garlic, cruciferous vegetables) to help glutathione production.
  • Limit excessive alcohol and manage weight, both of which influence liver health and choline needs.
  • Talk with your clinician before starting new supplements, especially if you have liver disease, pregnancy, or take other medications.

Genetic interpretations for rs10791957

Two effect alleles — AA (higher reliance on dietary choline)

If you have the AA genotype, you carry two copies of the effect allele. This variant reduces the efficiency of converting methionine into phosphatidylcholine. As a result, your body tends to make less phosphatidylcholine from dietary methionine and depends more on direct dietary choline.

Potential implications

  • Increased dietary choline needs to support liver function, membrane repair, and lipid transport.
  • Greater demand on methyl donors like SAMe and B vitamins to balance remethylation and antioxidant production.
  • Potentially higher risk of fatty liver if choline intake is insufficient, especially when combined with other risk factors such as excess alcohol or rapid weight gain.

Practical steps

  • Prioritize choline-rich foods: eggs, liver, soy, fish, and legumes.
  • Consider a choline supplement (phosphatidylcholine or choline bitartrate) if food intake is low; review dosing with your clinician.
  • Optimize B vitamins: ensure adequate folate and B12 through diet or a multivitamin to support remethylation and lower homocysteine.
  • Monitor liver health with clinical labs if you have symptoms or risk factors; discuss testing for homocysteine and liver enzymes with your healthcare provider.
One effect allele — AC (mildly reduced conversion)

If you have the AC genotype, you carry one copy of the effect allele. This causes a slight reduction in the efficiency of converting methionine to phosphatidylcholine. Your body may produce somewhat less choline from methionine and rely more on dietary choline than someone with two non-effect alleles.

Potential implications

  • Moderate increase in choline needs compared with the typical population.
  • Mild shifts in SAMe use and homocysteine handling that are usually manageable with diet and B vitamin support.

Practical steps

  • Include choline-rich foods more often: eggs, soy, fish, and lean meats or legumes.
  • If your diet is low in choline, consider a choline supplement; discuss amount with a clinician.
  • Support methylation by ensuring adequate folate and B12 intake through diet or a daily multivitamin.
  • Maintain healthy weight and limit alcohol to reduce liver stress.
Zero effect alleles — CC (typical conversion)

If you have the CC genotype, you carry two copies of the non-effect allele and are expected to have typical efficiency converting methionine into phosphatidylcholine. Your methylation and choline-generation processes are likely to function at standard levels.

Potential implications

  • Usual dietary choline and B vitamin needs similar to general population recommendations.
  • Standard support for methylation and liver health is typically adequate unless other risk factors are present.

Practical steps

  • Eat a balanced diet including choline-containing foods such as eggs, lean meats, legumes, soy, and fish.
  • Keep up with B vitamins through whole foods or a multivitamin if needed.
  • Monitor lifestyle factors that affect liver health: limit alcohol, maintain healthy weight, and stay active.

When to talk with your healthcare provider

  • If you have symptoms suggestive of liver problems, persistently elevated liver enzymes, or a family history of liver disease.
  • If you are pregnant, planning pregnancy, or breastfeeding, because choline needs are higher and supplementation may be considered only under clinical guidance.
  • If you are considering high-dose supplements, have chronic medical conditions, or take medications that affect methylation or liver function.
  • To order targeted blood tests when clinically appropriate: fasting homocysteine, serum B12, RBC folate, liver enzymes, and, if available, plasma choline.

PlexusDx provides educational genetic information only and does not provide medical advice. Always consult your healthcare provider before making changes to your diet, supplements, or medical care based on genetic information.