NutriStack
Grape Seed Extract and Vitamin C, a synergy.
Vitamin C helps regenerate oxidized proanthocyanidin antioxidants, and the two together support endothelial and vascular antioxidant capacity.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Grape Seed Extract and Vitamin C
- Pair type
- Synergy
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- +2 to your Stack Score (per scored synergy row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Synergy · Emerging evidence
Synergy
What is happening. Vitamin C helps regenerate oxidized proanthocyanidin antioxidants, and the two together support endothelial and vascular antioxidant capacity.
Mechanism. Vitamin C can reduce oxidized grape seed proanthocyanidins back to their active antioxidant form, recycling polyphenol antioxidant capacity and complementing nitric-oxide-mediated endothelial effects.
Recommendation. Reasonable to combine at standard doses for vascular or antioxidant support; no timing separation needed.
Sources (2)
- Bagchi D et al., Free radicals and grape seed proanthocyanidin extract: importance in human health and disease prevention, Toxicology, 2000
- Carr AC, Frei B, Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans, American Journal of Clinical Nutrition, 1999
Stack Score
How this pair moves the number.
Effect on the composite score
If both Grape Seed Extract and Vitamin C are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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