The chemical name for vitamin C in its biologically active form. L-ascorbic acid is a water-soluble vitamin essential for collagen synthesis, wound healing, immune function, and the absorption of iron from plant foods. Humans cannot synthesise it and must obtain it from fruit and vegetables, particularly citrus fruits, berries, kiwifruit, peppers, and leafy greens. As a food additive, designated E300, it serves as an antioxidant, preventing browning in cut fruit and protecting cured meats from nitrosamine formation. It is sensitive to heat, light, and oxygen, so cooking losses can be significant. Deficiency causes scurvy, once the scourge of long sea voyages.