Vitamin C, or L-ascorbic acid, is a water-soluble essential nutrient and potent antioxidant that protects cells from oxidative damage by free radicals. It plays a critical role in collagen synthesis, supporting wound healing, skin integrity, blood vessels, and bone health. Ascorbic acid enhances non-heme iron absorption from plant foods and contributes to immune function. Naturally abundant in citrus fruits, berries, peppers, and leafy greens, it is widely used as a food preservative, acidity regulator, and dietary supplement. Its enediol structure provides strong reducing properties, making it effective against oxidation in foods and biological systems. Deficiency leads to scurvy, characterized by fatigue, gum disease, and poor wound healing.