# Vitamin C (Ascorbic Acid / Liposomal) - Clinical Longevity Review & Consensus Audit

> **Consensus Verdict**: Extensively studied essential nutrient for immune defense, endothelial function, and collagen synthesis.

## 1. Executive Summary & Scores
- **Longevity Evidence Score**: **88/100**
- **Evidence Quality Tier**: **silver**
- **Human Clinical Evidence Strength**: 82/100
- **Primary Longevity Classification**: supplements
- **Safety Margin Score**: 84/100 (Higher is safer)
- **Time Burden**: ~15 minutes/day
- **Estimated Monthly Cost**: inexpensive
- **Adherence Friction**: 3/10 (Lower is easier to sustain)

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## 2. Biological Mechanisms of Action
Direct ROS neutralization & prolyl hydroxylase enzymatic cofactor

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## 3. Canonical Longevity Vector Impacts (The 8 Longevity Pillars)

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## 4. Practical Protocol & Administration Guidelines
- **Standard Clinical Dosage**: 500 mg – 1,000 mg
- **Recommended Timing**: Morning
- **Administration Type**: supplement
- **Recommended Biomarkers to Monitor**: immune_resilience, heart_health, skin_clarity

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## 5. Safety, Contraindications & Drug Interactions
- **Contraindications**: History of oxalosis / kidney stones at high doses (>2g)
- **Safety Profile**: Very High - Excess excreted in urine; gastrointestinal tolerance limit ~2,000 mg/day.

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## 6. Peer-Reviewed Human Clinical Trials & Key PMIDs
1. **Vitamin C and Immune Function** [PMID: 29099763]
   - Link: https://pubmed.ncbi.nlm.nih.gov/29099763/
2. **Vitamin C Supplementation Improves Endothelial Function in Cardiovascular Disease** [PMID: 24792921]
   - Link: https://pubmed.ncbi.nlm.nih.gov/24792921/
3. **The Roles of Vitamin C in Skin Health** [PMID: 28805671]
   - Link: https://pubmed.ncbi.nlm.nih.gov/28805671/
4. **Ascorbic Acid Reverses Endothelial Vasomotor Dysfunction in Patients with Coronary Artery Disease** [PMID: 8640968]
   - Link: https://pubmed.ncbi.nlm.nih.gov/8640968/

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## 7. Canonical Citation & Web Verification
- **Official Web Review**: [Vitamin C (Ascorbic Acid / Liposomal) on LongevityReviews](https://longevityreviews.org/modalities/vitamin-c)
- **Last Evidence Calibration**: 2026-08-09
- **Review Policy**: 0% sponsored placements, independent peer-reviewed consensus.