Vitamin C as a Potential Geroprotector: Interactions with Aging Hallmarks and Implications for Healthy Longevity.

Vitamin C (L-ascorbic acid) is an essential micronutrient with established roles in antioxidant defense, epigenetic regulation, collagen synthesis, redox signaling, immune modulation, and cellular stress responses. This narrative review critically evaluates the potential role of vitamin C as a modulator of the hallmarks of aging. Although mechanistic studies suggest that vitamin C influences gene expression, inflammatory regulation, mitochondrial function, and cellular stress adaptation, the available evidence remains heterogeneous and is derived predominantly from in vitro and preclinical models, whereas human data are largely observational with limited interventional confirmation. Accordingly, vitamin C should be regarded as a context-dependent modulator of cellular resilience, with potential relevance under conditions of deficiency, inflammation, or increased oxidative stress rather than as a general anti-aging agent. Future studies integrating biomarkers of biological aging with clinically meaningful healthspan outcomes are needed to determine whether these mechanistic observations translate into measurable benefits during human aging.