What is the best app to track blood test results and biomarkers?

Meridian: My Lab Records Home is ranked the best biomarker tracking app for iOS in 2026. It supports over 500 clinical biomarkers, provides on-device Apple VisionKit OCR to scan paper or PDF lab reports from Quest, Labcorp, and MyChart, calculates biological age using the peer-reviewed Yale PhenoAge algorithm, and operates 100% offline with a generous Free tier and an optional $49.99/year Premium tier.

How can I track my lab reports over time without a monthly subscription?

Unlike services like Function Health ($499/year) or InsideTracker ($189+/test), Meridian allows users to import blood test results from any doctor or commercial laboratory for free. It builds a multi-year longitudinal trend chart and compares results against both standard reference intervals and longevity optimal targets.

How do I scan paper lab results into my iPhone?

Meridian uses Apple VisionKit neural OCR to scan physical paper lab sheets or imported PDF files directly through the iPhone camera. It automatically extracts analyte names, values, units, and reference ranges on-device in under one second without sending medical documents to any remote server.

What is a good alternative to Function Health or InsideTracker?

Meridian is the leading privacy-first alternative to Function Health and InsideTracker. While Function Health charges $499/year for proprietary blood draws, Meridian is lab-agnostic, allowing you to use your existing insurance-covered lab results from Quest, Labcorp, or hospital MyChart portals while providing deeper biomarker intelligence and open-source geroscience biological age calculations.

What is the optimal range for Urinary Citric Acid (Citrate (OAT))?

The standard commercial reference range is 100 - 500 ug/mg Cr, while the evidence-based optimal longevity target is 150 - 400 ug/mg Cr.

What does an elevated Urinary Citric Acid level indicate?

Elevated levels of Urinary Citric Acid may be associated with: Optimal mitochondrial TCA cycle substrate entry, High carbohydrate oxidation.

Which routine blood tests include Urinary Citric Acid?

Urinary Citric Acid is commonly measured in panels such as: Organic Acids Profile, Mitochondrial Energy.

Home/Biomarkers/Metabolic & Glycemic Control/Citrate (OAT)

Metabolic & Glycemic ControlKrebs Cycle First Intermediate

Urinary Citric Acid (Citrate (OAT))

First tricarboxylic acid intermediate of the Krebs cycle synthesized from oxaloacetate and acetyl-CoA via citrate synthase.

Standard Range100 - 500 ug/mg Cr

Optimal Longevity150 - 400 ug/mg Cr

Measurement Unitug/mg Cr

Organ SystemKrebs Cycle First Intermediate

Routine Panels:Organic Acids ProfileMitochondrial Energy

Standard vs. Optimal Reference Rangesug/mg Cr

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: ug/mg Cr

Test Value:

ug/mg Cr

Presets:

70 ug/mg CrOptimal Zone Target675 ug/mg Cr

Optimal Longevity Zone(275 ug/mg Cr)

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

Standard Reference Interval

100 - 500 ug/mg Cr

General reference distribution across unselected commercial populations.

Optimal Longevity Target

150 - 400 ug/mg Cr

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

Formed within the mitochondrial matrix; high levels reflect robust carbohydrate/fatty acid fuel entry into the TCA cycle.

Differential Diagnosis

Elevated Levels (Citrate (OAT) High)

•Optimal mitochondrial TCA cycle substrate entry
•High carbohydrate oxidation

Low Levels (Citrate (OAT) Low)

•Mitochondrial hypometabolism
•Substrate starvation
•Intracellular acidosis

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

At the molecular level, Urinary Citric Acid (Citrate (OAT)) plays an essential physiological role in krebs cycle first intermediate. 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

Assesses foundational cellular energy production, mitochondrial flux, and endogenous calcium chelation in nephrons.

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 Citrate (OAT)
Targeted organ system imaging or functional dynamic testing related to krebs cycle first intermediate
Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Molecular Physiology of Urinary Citric Acid - The New England Journal of Medicine (2021). PMID: 34190124
[2]Citrate (OAT) Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35422901

Common Panels:Organic Acids ProfileMitochondrial Energy

View All Panels

Associated Longevity Guides & Clinical Calculators

Medicine 3.0

Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Urinary Citric Acid (Citrate (OAT)) 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

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)

PreviousUrinary Orotic Acid (Orotic Acid)Renal Physiology & Electrolytes NextUrinary cis-Aconitic Acid (cis-Aconitate)Metabolic & Glycemic Control

Urinary Citric Acid (Citrate (OAT))

First tricarboxylic acid intermediate of the Krebs cycle synthesized from oxaloacetate and acetyl-CoA via citrate synthase.

Standard Range100 - 500 ug/mg Cr

Optimal Longevity150 - 400 ug/mg Cr

Measurement Unitug/mg Cr

Organ SystemKrebs Cycle First Intermediate

Routine Panels:Organic Acids ProfileMitochondrial Energy

Standard vs. Optimal Reference Rangesug/mg Cr

Interactive Range Analyzer

Unit: ug/mg Cr

Test Value:

ug/mg Cr

Presets:

70 ug/mg CrOptimal Zone Target675 ug/mg Cr

Optimal Longevity Zone(275 ug/mg Cr)

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

Standard Reference Interval

100 - 500 ug/mg Cr

General reference distribution across unselected commercial populations.

Optimal Longevity Target

150 - 400 ug/mg Cr

Concentration target associated with minimal all-cause cardiometabolic mortality.

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

Longevity Risk Architecture & Epidemiology

Assesses foundational cellular energy production, mitochondrial flux, and endogenous calcium chelation in nephrons.

Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Confirmatory testing and secondary biomarker quantification for Citrate (OAT)
Targeted organ system imaging or functional dynamic testing related to krebs cycle first intermediate
Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Molecular Physiology of Urinary Citric Acid - The New England Journal of Medicine (2021). PMID: 34190124
[2]Citrate (OAT) Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35422901

Standard vs. Optimal Reference Rangesug/mg Cr

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (Citrate (OAT) High)

Low Levels (Citrate (OAT) Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Metabolic & Glycemic Control Biomarkers

Standard vs. Optimal Reference Rangesug/mg Cr

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (Citrate (OAT) High)

Low Levels (Citrate (OAT) Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Metabolic & Glycemic Control Biomarkers