The lack of folic acid in the body is called folic acid deficiency from a clinical point of view, and patients with a lack of folic acid in the body will experience symptoms of anemia, as well as skin damage, oral inflammation and anemia. The main symptoms are: 1. Skin damage: such as skin and mucous membrane lesions, seborrheic dermatitis, skin pigmentation and other symptoms; 2. inflammation of the oral cavity: such as lipitis, lingual inflammation, including ulcers of the mucous membrane in the oral cavity and other symptomatic manifestations; 3. megaloblastic anemia: which pregnant women, lactating women, infants, etc. are prone to folic acid deficiency, such as pregnant women lack of folic acid is easy to cause megaloblastic anemia, mental depression, hair yellowing, and even cause the development of the fetus is delayed, causing hare lip and so on. In addition, if the middle-aged or the elderly lack of folic acid may appear mental abnormalities, such as drooling, dizziness, headache and other symptoms, and even some of the elderly will also appear symptoms of dementia. Therefore, must pay attention to folic acid supplementation, such as found tongue inflammation, generalized skin lesions should seek medical attention.