As a whole, more than 55% of Chinese people lack of ; and more than 50% lack of . What's more, vitamin B1, B2, and C, are also commonly lacked among Chinese people. For the middle-aged and elderly people, the phenomenon of vitamin C deficiency is particularly serious. The five vitamins mentioned above are the vitamins that are most easily lacked in Chinese people in recently days.

Vitamin A is known as a "beautiful vitamin to make the eyes bright and the teeth white". This is because that the main function of vitamin A is to keep the healthy growth of the skin, hair, bones, and mucous membranes, and to enhance the eyesight and reproductive function. Vitamin A only exists in animal foods. Plant foods do not contain any vitamin A. They only contain the precursor of vitamin A——carotene, which can turn into vitamin A in human body.

Vitamin D deficiency usually occurs in the babies who are 2 months to 1 year old, pregnant women, or women during the lactation period. Once the children lack of vitamin D, they will easily suffer from rickets. The easiest way to supplement vitamin D is to get enough sunlight. Because there is a substance called as "7-dehydrogenase cholesterol" in human skin, which, under the irradiation of ultraviolet, can be transformed into vitamin D and be utilized by the body. Of course, it is also helpful to take in more cod liver oil, egg yolk, liver and so on.

The cereal products with germ and bran contain the highest content of vitamin B1. However, nowadays, most of the cooked wheaten foods have been refined and processed. In such a case, most of the vitamin B1 is lost in the processing.

The main sources of vitamin B2 are animal liver, as well as eggs, milk, meat, fish, green vegetables, beans and so on. In China, the vitamin B2 content in the diet structure is very limited, which is only half of the standard requirement. As a result, the phenomenon of vitamin B2 deficiency is very common in China.

Vitamin C is the main raw material for the formation of the mesenchyme of the cells. Its main role is to connect the cells together, keep the normal function of the teeth, blood vessels, bones and muscle, promote the healing of the wound, as well as enhance the resistibility of human body against diseases. The most common symptoms of vitamin C deficiency include bleeding of the gums, and subcutaneous punctate hemorrhage.