Vitamin A1 is found in the liver of mammals and saltwater fish as retinol. Vitamin A2 is found in the liver of freshwater fish. Carotenoids can decompose vitamin A. Food sources: livers of various animals, cod liver oil, whole milk, egg yolks, etc.

Physiological functions: 1. Maintain normal visual function; 2. Maintain the health of epithelial tissue cells; 3. Maintain normal bone development; 4. Promote growth and reproduction, body immunity and antioxidant.

Regular exposure to sunlight will prevent lack of it. It is not easily damaged by high temperatures. Food sources: marine fish, animal liver, egg yolks, cream and cheese.

Physiological functions: 1. Promote the absorption of calcium by the small intestinal mucosa; 2. Promote the calcification of bone tissue; 3. Promote the reabsorption of calcium and phosphorus by the renal tubules.

Physiological functions: 1. Antioxidant effect; 2. Maintain the integrity of red blood cells; 3. Regulate substance synthesis in the body. It may have certain effects on embryonic development and reproduction. Food source: vegetable oil. Vitamin E can only be synthesized in plants.

Physiological functions: 1. Blood coagulation; 2. Role in bone metabolism. Food sources include green vegetables, animal livers, and fish. The content is also high.

Vitamin B1 (Thiamine)

Vitamin B2 (riboflavin)

Vitamin B6

Vitamin B12 (cobalamin)

Physiological functions: Constituting coenzyme I (CoI) or nicotinamide purine dinucleotide (NAD) and coenzyme II (CoII) or nicotinamide adenine dinucleotide phosphate (NADP); protects cardiovascular systems. Deficiency can cause pellagra. The source of plant foods is mainly niacin, and animal foods are mainly nicotinamide. Liver, kidney, lean meat, fish and nuts.

Folic acid is also known as leaf essence, pteroyl glutamic acid, anti-anemia factor, vitamin M, vitamin U, etc. Physiological functions: Folic acid is reduced to physiologically active tetrahydrofolate in tissues such as the intestinal wall, liver, and bone marrow through the action of folate reductase. The main physiological role of tetrahydrofolate is that it is a coenzyme of the one-carbon unit transferase system in biochemical reactions in the body. Tetrahydrofolate carries these one-carbon units and binds them to plasma proteins, where they are primarily transported to the liver for storage.

Folic acid deficiency can cause fetal neural tube defects and megaloblastic anemia. Folic acid is only 50% bioavailable, compared to 85% when supplements are mixed with meals. Foods rich in folic acid include animal liver, kidney, eggs, beans, yeast, green leafy vegetables, fruits and nuts.

Vitamin C, also known as ascorbic acid, has physiological functions: 1. Participates in hydroxylation reactions (promotes collagen synthesis, promotes neurotransmitter synthesis, promotes steroid hydroxylation, and promotes hydroxylation and detoxification of organic matter or poisons. 2. Reduction (promotes antibody formation, promotes iron absorption, promote the formation of tetrahydrofolate, maintain the activity of thiolase); 3. Other functions (detoxification, cancer prevention, free radical scavenging).

Vitamin C deficiency can cause scurvy. Food sources: fresh vegetables and fruits. Vegetables are rich in peppers, chrysanthemum, bitter gourd, cabbage, beans, spinach, potatoes, leeks, etc.; fruits are rich in wild dates, red dates, strawberries, citrus, lemons, etc.