Vitamins are an organic compound necessary to maintain health. This kind of substance is neither the raw material of body tissue nor the source of energy in the body, but a kind of regulating substance, which plays an important role in substance metabolism. Because these substances cannot be synthesized in the body or the amount of synthesis is insufficient, although the amount needed is small, it always depends on food supply.
Classification of vitamins
1, fat-soluble vitamins: such as vitamin A, vitamin D, vitamin E and vitamin K, etc. Fat-soluble vitamins are characterized by being insoluble in water, soluble in fat and organic solvents, such as benzene solution, ether and chloroform. It often coexists with lipids in food, and the intake of fat-soluble vitamins in the intestine is related to the absorption of lipids. When the human body has lipid malabsorption, the absorption of fat-soluble vitamins is also greatly reduced. The absorbed fat-soluble vitamins are mainly stored in the liver and slowly excreted through bile;
2, water-soluble vitamins: such as vitamin B, vitamin C, folic acid, pantothenic acid, biotin, etc. are water-soluble vitamins. Water-soluble vitamins are soluble in water, but insoluble in fat and organic solvents. They can be excreted from the urine when ingested too much, can not be stored in the body, and are not easy to be poisoned by ingesting too much.
Both vitamins can exist in natural foods and participate in the regulation of human metabolism after absorption, but they do not participate in tissue and cell synthesis and do not provide energy. Fat-soluble vitamins and water-soluble vitamins play an important role in human growth and normal function maintenance. It is suggested to balance them in daily life and avoid some vitamin deficiency.
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