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Biomarker Encyclopedia

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Home/Biomarkers/Endocrinology & Hormones/VMR
Endocrinology & HormonesVitamin D Catabolic Flux

24,25(OH)2D to 25(OH)D Ratio (VMR)

Ratio of 24,25-dihydroxyvitamin D to 25-hydroxyvitamin D, reflecting the enzymatic catabolic activity of 24-hydroxylase (CYP24A1).

Standard Range0.06 - 0.14
Optimal Longevity0.08 - 0.12
Measurement UnitRatio
Organ SystemVitamin D Catabolic Flux
Routine Panels:Vitamin D Metabolite RatioCYP24A1 Workup

Standard vs. Optimal Reference RangesRatio

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: Ratio
Ratio
Presets:
0 RatioOptimal Zone Target1 Ratio
Optimal Longevity Zone(0.1 Ratio)

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

Standard Reference Interval

0.06 - 0.14

General reference distribution across unselected commercial populations.

Optimal Longevity Target

0.08 - 0.12

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

CYP24A1 initiates the multi-step inactivation pathway converting 25(OH)D and 1,25(OH)2D into inactive calcitroic acid.

Differential Diagnosis

Elevated Levels (VMR High)

  • •Normal robust vitamin D catabolism and clearance
  • •High CYP24A1 activity

Low Levels (VMR Low)

  • •Idiopathic infantile hypercalcemia (CYP24A1 mutation)
  • •Severe hypercalcemic nephrocalcinosis

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways
At the molecular level, 24,25(OH)2D to 25(OH)D Ratio (VMR) plays an essential physiological role in vitamin d catabolic flux. 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
Definitive diagnostic test for idiopathic infantile hypercalcemia caused by loss-of-function CYP24A1 mutations.
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 VMR
  • Targeted organ system imaging or functional dynamic testing related to vitamin d catabolic flux
  • Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
  • [1]Clinical Reference and Molecular Physiology of 24,25(OH)2D to 25(OH)D Ratio - The New England Journal of Medicine (2021). PMID: 33990124
  • [2]VMR Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35222901
Common Panels:Vitamin D Metabolite RatioCYP24A1 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 24,25(OH)2D to 25(OH)D Ratio (VMR) 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 Endocrinology & Hormones Biomarkers

High-Sensitivity C-Reactive Protein
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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