Vitamin C, also known as ascorbic acid, is a water-soluble essential vitamin that the human body cannot synthesize on its own and must be obtained through food or supplements. It performs several important functions in the body, including antioxidant activity, promoting collagen synthesis, boosting immunity, and aiding in iron absorption, thereby maintaining good health and normal metabolism. Vitamin C is widely found in fresh fruits and vegetables, such as oranges, lemons, kiwis, and green peppers, and is also commonly used as a nutritional supplement in health products and cosmetics. A deficiency in vitamin C can lead to health problems such as scurvy, weakened immunity, and slow wound healing, so maintaining an adequate intake is crucial for good health.