Yin deficiency can be improved by consuming medicinal foods such as wolfberry, lily of the valley and Colla Corii Asini. The effects of wolfberry are nourishing the liver and kidney, benefiting the essence and brightening the eyes (tonifying the essence and promoting the recovery of eyesight); the effects of lily are nourishing the yin and moistening the lungs (nourishing the lungs by replenishing the lungs with fluids), clearing the heart and calming the mind (stabilizing the mind by dispelling the inner vexation and heat); and Colla Corii Asini has the functions of tonifying the blood and nourishing the yin, moistening the dryness, and stopping the bleeding. 1. Lycium barbarum: used for deficiency of essence, lumbar and knee pain, dizziness and tinnitus, impotence and spermatorrhea, internal heat and thirst (internal heat accompanied by symptoms such as overeating, drinking, and urinating), and blood deficiency and atrophy. External solid heat, dampness and diarrhea in the spleen should be avoided. 2. Lily: used for yin deficiency and dry cough, labor cough and hemoptysis, false annoyance (body heat caused by the annoyance) palpitations. Wind-cold cough and cold loose stools (feces thin and unshaped) should not be taken. 3. Colla Corii Asini: Used for blood deficiency, dizziness and palpitation (rapid heartbeat, often accompanied by panic), muscle atrophy and weakness, restlessness and sleeplessness, internal movement of deficiency wind, coughing and dryness of the lungs, blood in the stool and leakage of blood (excessive menstruation or dripping), fetal leakage of pregnancy (small amount of bleeding from the vagina in the early stage of pregnancy), and so on. People with weak spleen and stomach, indigestion should not take it. Food therapy has a limited effect and is not as effective as medicine. If there are symptoms of yin deficiency, scientific treatment under the guidance of a doctor is recommended.