Since the human body cannot store large amounts of vitamin C, it must be obtained from food. The anti-cancer effect of vitamin C is also receiving increasing attention. Dr. Hiroshi Ohshima of the Environmental Carcinogenesis Department of the International Agency for Research on Cancer, World Health Organization, fed rats non-carcinogenic nitrosoproline and nitrite, and then fed them vitamin C. Results showed that vitamin C inhibited the synthesis of nitrosamine (a carcinogen) by 97.5%. Tea is rich in vitamin C, especially green tea, whose vitamin C content is much higher than that of most vegetables. Every 100 grams of green tea contains about 180 mg of vitamin C, while high-quality green tea can contain up to 500 mg. General-strength tea soup contains about 2-4 mg of vitamin C per 100 ml.

The vitamin A precursor in tea, namely carotene, is also higher than that in ordinary vegetables. Carotene has the physiological function of vitamin A. Every 100 grams of tea contains about 5.46 mg of carotene. Vitamin B1 can prevent and treat polyneuritis. Every 100 grams of tea contains 0.07 mg, which is 7 times the content in apples. Vitamin B2 is an active substance necessary for maintaining normal retinal function. Every 100 grams of tea contains as much as 1.20 mg, which is about 5 times higher than that in vitamin B2-rich soybeans, 20 times higher than that in rice, and 60 times higher than that in melons and fruits.

Tea also contains vitamin P, which is related to the activity of human microvessels. As early as the 1950s, Kulsanov and others in the former Soviet Union found that tea leaves contain large amounts of vitamin P-like substances, such as D, L-catechin and L-epicatechin. The content per gram of dry tea is 14 mg in total, and L-epicatechin gallate is 16 mg. Drinking tea (especially green tea) with high catechin content as a hot beverage will help the human body supplement vitamin P. Researchers at the Moscow Institute of Biochemistry found that the content of vitamin C and vitamin P in tea is 4 times that in lemon juice and orange juice.

These components play a certain role in preventing scurvy. If the human body lacks vitamin PP (i.e., nicotinic acid), it can cause pellagra, diarrhea, and dementia. The content of vitamin PP in tea is much higher than that in vegetables and fruits. Every 100 grams of tea contains 4.7 mg of vitamin PP, while Chinese cabbage contains only 0.3 mg, and watermelon contains only 0.2 mg. Vitamin K is an anti-hemorrhagic substance. Tea contains about 300-500 international units of vitamin K.

Folic acid is an important member of the B vitamin family. It plays an important role in preventing anemia, but it is often lacking in ordinary foods. Analysis by the University of California, USA, suggests that Chinese green tea contains a relatively high amount of folic acid. Food science researchers at the University of California further pointed out that drinking 5 cups of green tea a day can provide one-fourth of the daily folic acid requirement. British tea expert Mr. Harler also pointed out that thiamine, riboflavin, nicotinic acid, and pantothenic acid in tea can form the vitamin B complex. If you drink 6 cups of tea a day, it can provide one-tenth of the daily requirement of the vitamin B complex.

Since tea contains a variety of vitamins, under normal brewing conditions, the leaching rate can reach about 80%. Therefore, drinking tea in moderation is of great benefit to supplementing the body with a certain amount of certain vitamins.