Vitamin C, also known as ascorbic acid, is an extremely important vitamin in the human body and constitutes an important part of human vital signs. A lack of vitamin C will not only increase the degree of melanin deposition in the skin, but will also greatly increase the incidence of cancer, and the most direct disease of severe vitamin C deficiency is scurvy. Vitamin C is commonly found in plants, but there is no shortage of people who are deficient in the vitamin. Initially, patients usually have gums that bleed more easily, swelling, pallor, mild anemia, rough skin, and scarring, wounds that are difficult to recover from, mouth ulcers, and slight loosening and loss of teeth. In younger children, there is a risk of periosteal bleeding and even paralysis, swollen joints, low immunity, easy catching of colds, and susceptibility to infectious diseases. In the later stages of the disease patients may develop serious skin and oral problems, oral ulcers that are difficult to heal, depression, laxity, severe symptoms in the periosteum, and even severe immune deficiency, digestive system dysfunction, metabolic dysfunction, and for students, memory loss and poor concentration may occur. In short, the initial symptoms of vitamin c deficiency, mainly oral problems, daily attention should be paid to eat more vegetables, especially oranges rich in vitamin c.