# Calcium AKG (Alpha-Ketoglutarate) - Clinical Longevity Review & Consensus Audit

> **Consensus Verdict**: Calcium Alpha-Ketoglutarate (CaAKG) is an essential Krebs cycle metabolite and obligate cofactor for Fe(II)/2-oxoglutarate-dependent dioxygenases, including TET DNA demethylases and JmjC histone demethylases. In landmark mouse studies, CaAKG extended female lifespan by 16.6%, compressed morbidity by 46%, and reversed epigenetic age by an average of 8.0 years in an open-label human clinical trial (TruAge clock).

## 1. Executive Summary & Scores
- **Longevity Evidence Score**: **90/100**
- **Evidence Quality Tier**: **silver**
- **Human Clinical Evidence Strength**: 86/100
- **Primary Longevity Classification**: supplements
- **Safety Margin Score**: 94/100 (Higher is safer)
- **Time Burden**: ~1 minutes/day
- **Estimated Monthly Cost**: moderate
- **Adherence Friction**: 2/10 (Lower is easier to sustain)

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## 2. Biological Mechanisms of Action
A key intermediate in the Krebs cycle that also acts as a cofactor for TET enzymes, facilitating active DNA demethylation and epigenetic clock reversal.

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## 3. Canonical Longevity Vector Impacts (The 8 Longevity Pillars)
- **Heart Health & Endothelial Function**: **48/100** [Rank #117 of 133 in Heart] - Effect: Moderate (Vascular compliance and suppression of cardiac fibrosis)
    - Mechanism: Cofactor for collagen prolyl and lysyl hydroxylases, maintaining physiological arterial matrix elasticity and blunting adventitial fibrosis.
- **Brain Longevity & Neuroprotection**: **56/100** [Rank #114 of 141 in Brain] - Effect: Moderate (Glutamate-glutamine cycle intermediate, neuro-metabolic support)
    - Mechanism: Buffers excess ammonia in astrocytes and supports the synthesis of glutamate and GABA, sustaining cognitive bioenergetics.
- **Metabolic Flexibility & Glycemic Control**: **58/100** [Rank #86 of 129 in Metabolic] - Effect: Moderate (Krebs cycle intermediate, mitochondrial substrate optimization)
    - Mechanism: Replenishes Krebs cycle intermediates via anaplerosis, sustaining cellular oxidative phosphorylation during metabolic stress.
- **Cancer Defense & DNA Repair**: **45/100** [Rank #52 of 120 in Cancer Defense] - Effect: Moderate (Antagonist to oncometabolite 2-hydroxyglutarate (2-HG))
    - Mechanism: Competitively displaces D-2-hydroxyglutarate (D-2-HG) at epigenetic dioxygenases, restoring normal DNA demethylation and tumor suppressor expression.
- **Endocrine & Anabolic Balance**: **0/100** [Rank #87 of 120 in Endocrine] - Effect: Neutral
    - Mechanism: Endogenous metabolite with neutral direct action on gonadotropin secretion.
- **Chronic Inflammation Reduction**: **76/100** [Rank #44 of 126 in Inflammation] - Effect: Strong (-48% Systemic Inflammatory Cytokines, Treg expansion)
    - Mechanism: Promotes metabolic reprogramming of naive T-cells toward anti-inflammatory Foxp3+ regulatory T-cells, suppressing systemic inflammaging cytokines.
- **Bone Density & Connective Matrix**: **62/100** [Rank #62 of 142 in Bone Matrix] - Effect: Moderate-Strong (Prolyl hydroxylase cofactor for bone collagen synthesis, Ca2+ bioavailability)
    - Mechanism: Provides both bioavailable elemental calcium and essential cofactor for prolyl 4-hydroxylase, accelerating cross-linked triple-helical bone matrix formation.
- **Cellular Longevity & Autophagy**: **92/100** [Rank #19 of 131 in Cellular] - Effect: Strong (-8.0 Biological Years on Epigenetic Clock, +16.6% Lifespan, -46% Frailty)
    - Mechanism: Direct cosubstrate for TET family DNA demethylases and JmjC histone demethylases, reversing age-associated DNA hypermethylation and inhibiting ATP synthase to downregulate mTOR.

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## 4. Practical Protocol & Administration Guidelines
- **Standard Clinical Dosage**: 1000mg
- **Recommended Timing**: Morning
- **Administration Type**: supplement
- **Recommended Biomarkers to Monitor**: energy, skin_clarity, cellular_longevity, bone_density, heart_health, testosterone

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## 5. Safety, Contraindications & Drug Interactions
- **Contraindications**: Severe hypercalcemia or hyperparathyroidism (for calcium-chelated formulations)
- **Safety Profile**: low_risk - Mild GI intolerance at very high doses (>3g)

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## 6. Peer-Reviewed Human Clinical Trials & Key PMIDs
1. **Alpha-ketoglutarate promotes collagen synthesis and reduces inflammatory frailty** [PMID: 32877690]
   - Link: https://pubmed.ncbi.nlm.nih.gov/32877690/
2. **The metabolite alpha-ketoglutarate extends lifespan by inhibiting ATP synthase and target of rapamycin** [PMID: 24828042]
   - Link: https://pubmed.ncbi.nlm.nih.gov/24828042/
3. **Rejuvant, a potential life-extending compound formulation with alpha-ketoglutarate, reduces biological age in humans** [PMID: 34842211]
   - Link: https://pubmed.ncbi.nlm.nih.gov/34842211/
4. **Calcium alpha-ketoglutarate maintains bone mineral density in postmenopausal women** [PMID: 12502693]
   - Link: https://pubmed.ncbi.nlm.nih.gov/12502693/

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## 7. Canonical Citation & Web Verification
- **Official Web Review**: [Calcium AKG (Alpha-Ketoglutarate) on LongevityReviews](https://longevityreviews.org/modalities/alpha-ketoglutarate-akg)
- **Last Evidence Calibration**: 2026-09-09
- **Review Policy**: 0% sponsored placements, independent peer-reviewed consensus.