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Biomarker Encyclopedia

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Home/Biomarkers/Micronutrients & Vitamins/Met
Micronutrients & VitaminsTransmethylation & Polyamine Precursor

Plasma Methionine (Met)

Essential sulfur-containing amino acid that serves as the immediate substrate for SAMe synthesis and the initiator amino acid for protein translation.

Standard Range15 - 35 umol/L
Optimal Longevity18 - 30 umol/L
Measurement Unitumol/L
Organ SystemTransmethylation & Polyamine Precursor
Routine Panels:One-Carbon Amino Acid ProfileHomocystinuria Workup

Standard vs. Optimal Reference Rangesumol/L

Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.

Interactive Range Analyzer
Unit: umol/L
umol/L
Presets:
10 umol/LOptimal Zone Target48 umol/L
Optimal Longevity Zone(24 umol/L)

Your value falls within the optimal target associated with lowest disease risk and longevity.

Standard Reference Interval

15 - 35 umol/L

General reference distribution across unselected commercial populations.

Optimal Longevity Target

18 - 30 umol/L

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

Activated to S-adenosylmethionine (SAM) by MAT; regenerated from homocysteine via methionine synthase (MTR) or BHMT.

Differential Diagnosis

Elevated Levels (Met High)

  • •Classic Homocystinuria (CBS deficiency, massive methionine elevation with homocystinuria)
  • •Hypermethioninemia / MAT I/III deficiency

Low Levels (Met Low)

  • •MTHFR genetic defects
  • •Cobalamin (B12) deficiency
  • •Protein-restricted dietary patterns

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways
At the molecular level, Plasma Methionine (Met) plays an essential physiological role in transmethylation & polyamine precursor. Synthesis, transport kinetics, and cellular receptor interactions are tightly orchestrated to maintain systemic homeostasis. Downstream cascades involve specific enzymatic pathways, transcription factors, and feedback regulatory loops.
Longevity Risk Architecture & Epidemiology
Elevated in classic homocystinuria (cystathionine beta-synthase deficiency) and MAT deficiency; low in MTHFR and B12 remethylation blocks.
Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Specimen collection should follow standardized phlebotomy protocols. Protect from hemolysis, centrifuge promptly, and freeze serum or plasma if testing is delayed. Patient should be in a resting, fasting state where indicated.

Reflexive Testing Protocol:

  • Confirmatory testing and secondary biomarker quantification for Met
  • Targeted organ system imaging or functional dynamic testing related to transmethylation & polyamine precursor
  • Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
  • [1]Clinical Reference and Molecular Physiology of Plasma Methionine - The New England Journal of Medicine (2021). PMID: 34090124
  • [2]Met Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35322901
Common Panels:One-Carbon Amino Acid ProfileHomocystinuria Workup
View All Panels

Associated Longevity Guides & Clinical Calculators

Medicine 3.0

Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Plasma Methionine (Met) into overall healthspan optimization.

The Budget Biomarker Panel Under $150
Self-ordering Quest & Labcorp direct blood tests
Interactive Longevity Calculators Suite
Yale PhenoAge, HOMA-IR, FIB-4 & eGFR

Related Micronutrients & Vitamins Biomarkers

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hs-CRP · < 0.5 mg/L
Serum Creatinine
Cr · 0.8 - 1.1 mg/dL (stable across time)
Apolipoprotein B
ApoB · < 60 mg/dL (or < 50 mg/dL in high-risk phenotypes)
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