Methylation cycle – Vitamin B12

 

Found this really cool picture that explains what the Methylation Cycle does:

 

 

 

Vitamin B12

The bridge between the Folate cycle and the Methylation cycle that produces Methionine, the enzymes are regulated by the MTR and MTRR genes. (Amendment suggested by Dr Louise Lindenberg).

 

🔹 What Is Vitamin B12?

• A water-soluble B-vitamin
  
• Essential for your brain, nerves, red blood cells, and DNA production
• Works closely with folate and vitamin B6
  
  

🔧 What Does It Do?

Function	Role
🧠 Brain & Nerve Health	Maintains nerve insulation (myelin), supports mood and memory
🩸 Red Blood Cell Formation	Prevents megaloblastic anaemia (large, immature red blood cells)
🧬 DNA Synthesis	Needed for proper cell division and DNA repair
🧪 Homocysteine Regulation	Converts homocysteine to methionine (with folate & B6)
⚙️ Energy Metabolism	Helps convert food into energy

🥩 Food Sources of Vitamin B12

Category	Examples
🥩 Animal Sources	Liver, beef, eggs, fish, poultry, dairy
🥛 Fortified Foods	Plant-based milks, cereals, nutritional yeast (fortified only)
❌ Not in Plants Naturally	Vegans need supplements or fortified foods

⚠️ Signs of Deficiency

Symptom	What It Means
Fatigue	Low red blood cell production
Tingling/Numbness	Nerve damage (hands, feet)
Memory Issues	Cognitive decline, confusion
Glossitis	Sore, swollen tongue
Pale Skin	Anemia
Depression or Mood Swings	Linked to neurotransmitter disruption

People at risk:

• Vegans/vegetarians
  
• Elderly
  
• People with low stomach acid or GI issues (like celiac, IBD)
  
• Those taking metformin or acid blockers
  

💊 RDA (Recommended Daily Allowance)

Group	Amount
Adults	2.4 mcg/day
Pregnant	2.6 mcg/day
Breastfeeding	2.8 mcg/day

B12 is stored in the liver, so deficiencies can take years to show up.

✅ Best Forms of B12 for Methylation Support

Form	Best For	Why It Helps
Methylcobalamin	✅ Methylation issues, MTHFR SNPs	Already in the active, methylated form used by your body. Supports conversion of homocysteine → methionine.
Adenosylcobalamin	Mitochondrial/energy issues	Active form used in the mitochondria for energy metabolism. Pairs well with methylcobalamin.
Hydroxocobalamin	Detox support, long-acting	Converts slowly into methyl- and adenosylcobalamin. Useful if you’re sensitive to methyl donors. Good for nitric oxide balance.
Cyanocobalamin	Not recommended for methylation issues	Synthetic, inactive form that requires conversion. May be poorly used in people with SNPs or methylation defects.

🔹 If You Have an MTHFR Mutation:

• Methylcobalamin is usually the best choice.
  
• Combine with 5-MTHF (not folic acid) for optimal support.
  
• Some people do well with a mix of methylcobalamin + adenosylcobalamin.
  

⚠️ Sensitive to Methyl Groups?

If you feel overstimulated, anxious, or wired on methylcobalamin:

• Try hydroxocobalamin (gentler and slower-acting)
  
• Start with low doses and increase gradually
  

🧬 Bottom Line

If you…	Then take…
Have MTHFR or high homocysteine	Methylcobalamin
Are sensitive to methyl donors	Hydroxocobalamin or very low-dose methylcobalamin
Need energy support	Methyl + Adenosyl combo
Are you taking standard multivitamins	Avoid cyanocobalamin if you have methylation SNPs

🧬 How B12 Works with Folate and MTHFR

• B12 helps convert homocysteine → methionine, a key part of the methylation cycle
  
• Without enough B12, folate gets “trapped” and can’t be used properly — this is called the “methyl trap”
  
• Even if you have enough folate, a B12 deficiency mimics folate deficiency

Alex’s Results:

MTR	2756 A>G	AA	normal
MTRR	66 A>G	GG	moderately impacted

MTRR 66 A>G – Methionine Synthase Reductase is a helper enzyme that keeps another enzyme (called Methionine Synthase) working properly. This main enzyme needs vitamin B12 (in its active form, methylcobalamin) to do its job.

That job includes:

• Helping your body make methionine, an important amino acid.

• Controlling levels of homocysteine, a substance that can damage blood vessels if it builds up too much.

If someone has the GG version of the gene:

• Their enzyme may not work as well, especially if their vitamin B12 is low.

• This can raise their risk for heart problems (like premature coronary artery disease) and birth defects (like neural tube defects).

What to do:
Make sure the person gets enough:

• Folate (vitamin B9)

• Vitamin B12

• Vitamin B6

These nutrients help the enzymes function properly and maintain safe homocysteine levels.

Foods rich in B12

PLEASE NOTE: ANY VIEWS REGARDING THE RESULTS ARE MY UNDERSTANDING AND DO NOT SERVE AS PROFESSIONAL ADVICE. THE TREATMENT RECOMMENDATION IS STRICTLY RELATED TO ALEX’S RESULTS AND NOT MEANT FOR SELF-TREATMENT. ALWAYS SPEAK TO YOUR HEALTHCARE PROVIDER BEFORE STARTING ANY TREATMENTS.