The methylation cycle is a set of biochemical reactions that move one-carbon units through folate, B12, methionine, and homocysteine pathways.
Why it matters in personalization
The cycle appears in personalization because it connects genes, diet, lab markers, and product forms. That makes it useful for asking better questions, not for turning a pathway diagram into a supplement plan. A pathway can explain a possible mechanism of action without proving a user-level outcome.
Core inputs
Folate, vitamin B12, vitamin B6, riboflavin, choline, methionine intake, medications, and health context can all affect methylation-related markers. Genetic context such as an MTHFR variant may modify interpretation, but it does not replace labs or observed response.
Common marker context
Homocysteine is the marker most often discussed with this cycle. It can be influenced by nutrient status, kidney function, thyroid status, medications, age, and other factors. One marker should be interpreted with the rest of a blood biomarker panel, not as a stand-alone score.
Why pathway logic can mislead
The cycle is often described as if adding one nutrient will push the whole system in the desired direction. Human metabolism has feedback loops, transport limits, and competing needs. That is why recommendation ranking should treat methylation claims as evidence-weighted context, not deterministic instructions.
How this appears in Unfair
Unfair can surface methylation-cycle context when explaining folate forms, B-vitamin labels, and lab-linked goals. The app should keep genotype, labels, symptoms, and labs visually separate so users can see which signal is doing the work.
Safety note
Symptoms, abnormal labs, pregnancy context, and medication overlap should be reviewed with a clinician before acting on methylation-related interpretations.