I used to have oral ulcers. At first, I thought it was a lack of vitamin B2 (riboflavin). I ate a lot of vitamin B2, which was ineffective. Later, I heard that it was caused by excess heat of spleen and stomach. It is true that when the mouth and tongue are sore, the stool is dry and the urine is yellow. The book says that it is appropriate to eat something that clears away heat and purges fire and cools the serum and intestines. I ate Wanqing. I ate a little too much. I had diarrhea, but my oral ulcer got better. Pregnant women should not eat more. Later I heard that it was zinc deficiency. People who are deficient in zinc will also catch repeated colds. Zinc is a component of many important enzymes in human body, which has a catalytic effect on life activities. Foods rich in zinc include oysters, oysters, liver, Tricholoma, sesame, lean meat, eggs, peanuts, walnuts and scallops. The fried pork liver I ate really worked. This is my experience. Zinc-selenium tablets, calcium-iron-zinc-selenium tablets and protein zinc selenium are all good choices. Tip: zinc supplementation should also be appropriate, and the amount of zinc supplementation in daily diet should not exceed 45 mg.