The effect of vitamin C on skin condition and health - mechanisms of action, clinical evidence, and therapeutic applications

Vitamin C (L-ascorbic acid) is a crucial water-soluble antioxidant and a cofactor in multiple enzymatic processes essential for skin health. This review discusses the biochemical mechanisms of vitamin C function, clinical evidence of its efficacy, and its therapeutic applications in dermatology and cosmetology. Vitamin C is transported into the skin by sodium-dependent vitamin C transporters (SVCT1 and SVCT2), ensuring high intracellular concentration that protects against oxidative stress, supports collagen synthesis, and modulates melanogenesis. Topical and oral vitamin C have been shown to improve skin elasticity, reduce wrinkles and hyperpigmentation, and provide photoprotection against UV-induced damage. Clinical studies confirm its beneficial effects in photoaging, wound healing, and the management of inflammatory and neoplastic skin diseases, including atopic dermatitis, acne, and melanoma. However, limitations such as variable bioavailability, formulation instability, and heterogeneity in study designs remain challenging. Further research is needed to standardize dosing, optimize delivery systems, and clarify its role as an adjuvant therapeutic in dermatology. Vitamin C remains a key ingredient in evidence-based strategies for maintaining skin health and combating aging and disease.