Vitamins are a class of organic compounds necessary for maintaining good health. These substances are neither the raw materials for the body tissue nor the source of energy in the body, but a kind of regulating substances, which play an important role in the metabolism of substances. Since these substances cannot be synthesized in the body or the amount of synthesis is insufficient, although the required amount is very small, they must always be supplied by food.

Vitamins, also known as vitamins, are commonly referred to as life-sustaining substances. They are a class of organic substances necessary to maintain human life activities, and are also important active substances to maintain human health. The content of vitamins in the body is very small, but indispensable. Although the chemical structures and properties of various vitamins are different, they have the following things in common:

①Vitamin is present in food in the form of provitamin;

②Vitamin is not a component of body tissues and cells, nor does it produce energy, its role is mainly to participate in the regulation of body metabolism;

③ Most of the vitamins cannot be synthesized by the body or the synthesis amount is insufficient to meet the needs of the body, and must often be obtained through food;

④ The human body has a very small requirement for vitamins, and the daily requirement is often calculated in milligrams or micrograms, but once it is deficient, it will cause corresponding vitamin deficiency and cause damage to human health.

Vitamins are different from the three major substances of carbohydrates, fats and proteins. They only occupy a very small proportion in natural foods, but they are necessary for the human body. Some vitamins such as B6, K, etc. can be synthesized by bacteria in the intestinal tract of animals, and the synthetic amount can meet the needs of animals. Animal cells can convert tryptophan into niacin (a B vitamin), but the amount produced is not sufficient; vitamin C can be synthesized by other animals except primates and guinea pigs. Plants and most microorganisms can synthesize their own vitamins, and do not have to be supplied by the body. Many vitamins are components of prosthetic groups or coenzymes.

Vitamins are some small amounts of organic compounds necessary for human and animal nutrition and growth, and play an extremely important role in the body's metabolism, growth, development and health. If a certain vitamin is lacking for a long time, it will cause physiological dysfunction and a certain disease will occur. Usually obtained from food. There are dozens of species found at this stage, such as vitamin A, vitamin B, vitamin C and so on.

Vitamins are essential organic compounds in human metabolism. The human body is like an extremely complex chemical factory, constantly undergoing various biochemical reactions. The reaction is closely related to the catalysis of enzymes. For enzymes to be active, coenzymes must be present. Many vitamins are known to be coenzymes of enzymes or to be constituent molecules of coenzymes. Therefore, vitamins are important substances to maintain and regulate the normal metabolism of the body. Arguably, the best vitamins are in the form of "bioactive substances" that exist in human tissues.