BRS2(KC1) - Methyl Donor Sufficiency

1. Definition

Availability of folate, B12, choline, and betaine required for one-carbon transfer and remethylation.

2. Constraint Role

Availability of folate, B12, choline, and betaine required for one-carbon transfer and remethylation. Dietary methyl donors and related substrates supply substrate and cofactor context for dependent mechanisms in this BRS.

3. Supporting Inputs/Substrates

• B12 ← dairy, seafood, liver
• Betaine ← beetroot, spinach
• Choline ← eggs, liver
• Folate ← leafy greens, legumes, liver

4. Biological Importance

Availability of folate, B12, choline, and betaine required for one-carbon transfer and remethylation. Inadequate coverage of these inputs can limit one-carbon flux, remethylation, and downstream methylation-dependent processes across linked FMs and PMs.

5. Connected Mechanisms

• Functional Mechanisms
  • BRS2(FM1) - Methylation Cycle Efficiency
  • BRS2(FM3) - Methylation–Membrane Coupling
• Primary Mechanisms
  • BRS2(PM1) - Folate/B12-Dependent Homocysteine Remethylation
  • BRS2(PM2) - Betaine/BHMT Remethylation
  • BRS2(PM4) - Methionine Cycle Flux
  • BRS2(PM7) - Phospholipid Methylation

6. Constraint Stressors / Burdens

• inconsistent methyl-donor intake across days
• low folate, B12, choline, or betaine food patterns where KC1 applies
• inadequate sulfur amino-acid and glycine supply where KC2 applies
• ultra-processed dietary patterns displacing whole-food methyl-donor sources

7. References

1. See linked FM pages for cited evidence.