Vitamins are a kind of trace organic substances that humans and animals must obtain from food in order to maintain normal physiological functions. Vitamins play an important role in the growth, metabolism and development of the human body. Vitamins participate in the human body's biochemical reactions and regulate the human body's metabolic function. Most vitamins cannot be synthesized or stored in the body, and generally need to be obtained from food. If the diet lacks a certain vitamin or the absorption and utilization rate of vitamins is reduced, a series of symptoms will occur.