WATER SOLUBLE VITAMINS

Vitamin C (ascorbic acid) is colorless crystals with acidic taste.

Ascorbic acid participates in the redox processes. It is involved in the synthesis of collagen, folic acid, adrenal hormones, and tryptophan. It is important in the breakdown of hemoglobin in tissues. Vitamin C enhances the synthesis of immunoglobulins.

Deficiency of vitamin C leads to lessening of organism weight, weakness, shortness of breath, heart pain, decreasing of immunocompetence. In severe cases scurvy develops. The permeability and fragility of blood vessels increase. There are spontaneous hemorrhages, and loss of teeth. The basis for these phenomena is disorders of collagen synthesis.

Source of vitamin C for humans are canker berry, black currants, mountain ash, red pepper, tomatoes, lemons, and cabbage. Daily requirement is 75 mg.

Vitamin B₁ (thiamine) is the first crystalline vitamin produced in the laboratory. It contains pyrimidine and thiazole rings having a methylene bridge.

The active form of thiamine is thiamine pyrophosphate (TPP,or cocarboxylase). It is part of the five enzymes involved in intermediate metabolism. Usually it is decarboxylation reactions. TPP is connected with energy releasing reactions.

Symptoms of avitaminosis В₁ are disruption of the digestive system, mental disorders (hallucinations), degenerative changes in nerve endings and the vascular bundles, atrophy and paralysis of limbs, depression of the cardiovascular system. The В₁-avitaminosis results in disease called ("beri-beri"polyneuritis), which can lead to paralysis and death.

Sources of vitamin В₁ are yeast, cereals, nuts, bread from meal, when the grain during processing does not lose the embryos and membranes. In animal products it is found in the liver, kidneys and brain. Daily requirement is 1.2 mg.

Vitamin B₂ (riboflavin). The basis of the riboflavin molecule is isoalloxazine, which combines benzene, pyrazine and pyrimidine rings. It is a substance of yellow color.

The ability of riboflavin to be easily oxidized and restored is the basis of its biological effects. Riboflavin is a coenzyme of oxidoreductases (part of the FAD and FMN).

Riboflavin deficiency lead to the stop of hair growth, loss of hair, dermatitis, mucous membranes damage (especially in the corners of the mouth), fatigability, decrease in working capacity, disruption of normal hemoglobin synthesis; muscular weakness.

Sources of vitamin В₂ are milk, meat, liver, kidney, eggs, yeast, green vegetables, cereals, fruits. Daily requirement is 1.7 mg.

Vitamin В₆ (pyridoxine)is a derivative of 3-oxypyridine. It presents itself with pyridoxole, pyridoxal and pyridoxamine, all of them in the organism are able to transform to the pyridoxal phosphate, which participates in chemical reactions.

Pyridoxal phosphate is the prosthetic group of carboxylases and transaminases involved in the formation of biogenic amines, transformation of amino acids, and synthesis of heme of hemoglobin.

В₆ deficiency disease involves violations of the metabolism of proteins and amino acids. The main symptoms are a violation of hematopoiesis and the development of various types of dermatitis that cannot undergo the treatment with nicotinic acid. В₆-vitamin deficiency is also accompanied by violation of lipid metabolism that leads to the development of atherosclerosis.

Sources of pyridoxine are beef, fish, peas, egg yolk and green parts of plants. Daily requirement is 2 mg. Since vitamin B₆ is widely distributed in foods and can be partially synthesized by intestinal micro flora, in normal conditions, B₆-deficiency disease in humans has not been observed.

Vitamin B₁₂ (cobalamin). It contains the grouping of four pyrrol rings with Co atom in the center.

Derivatives of B₁₂ coenzymes are composed of a number of enzymes that accelerate the most important reactions of nitrogen-containing compounds, carbohydrate, nucleic acid and lipid metabolism. B₁₂ is involved in transmethylation reactions, intramolecular transfer of H atoms and various functional groups (hydroxyl, amine, etc.).

With a lack of vitamin B₁₂ disruption of hematopoiesis in bone marrow occurs, causing anemia malignant megablastic, disruption of the nervous system, reducing the acidity of gastric juice.

Vitamin B₁₂ is the only vitamin the synthesis of which is carried out only by microorganisms. Sources of cobalamin: meat, beef liver, fish, milk and eggs. Plants do not contain vitamin B₁₂. Depot of vitamin B₁₂ in humans is in the liver, where it accumulates in the amount of a few milligrams. Daily requirement is 3 micrograms.

Vitamin B₅ (pantothenic acid) is found in all animal, plant and microbial objects (Greek pantos - everywhere).

Pantothenic acid is a part of coenzyme A. CoA is involved in transfer reactions of acyl groups. A number of biochemical reactions are associated with CoA that underlies the oxidation and fatty acid synthesis, the biosynthesis of fats, oxidation of breaking up products of carbohydrates.

In the absence of vitamin B₅ there can be dermatitis, slow growth, there is weight loss, hair loss and depigmentation of hair, degenerative changes in the nervous system. Discoordination of movements, paralysis, disruption of the gastrointestinal tract, reproductive organs and adrenal glands can be related to this.

In humans, B₅ vitamin deficiency is rare as pantothenic acid is produced by intestinal micro flora. Sources are yeast, milk, eggs, liver, kidneys, peas, cauliflower, potatoes, tomatoes. Daily requirement is 10 mg.

Vitamin PP (nicotinic acid and nicotinamide, niacin, B₃) is a derivative of pyridine. Vitamin PP is involved in all types of metabolism: carbohydrate, protein and lipid. Nicotinamide is a part of the most important coenzymes – NAD⁺ (nicotinamide adenine dinucleotide) and NADP⁺ (nicotinamide adenine dinucleotide phosphate), involved in redox reactions. Vitamin PP is necessary for energy production.

Avitaminosis PP is expressed in an inflammation of the mucous membranes of the gastrointestinal tract, and then a skin inflammation (dermatitis) on the areas which are exposed to the sun irradiation. It is a pellagra disease. Also damage of the brain is observed. So, it is a disease of 3D: dermatitis, diarrhea, dementia.

Sources of vitamin PP for humans are liver and kidneys of animals, yeast, buckwheat, beans, etc. A certain amount of nicotinic acid is synthesized in the human organism from the amino acid tryptophan. Daily requirement is 18 mg.

Folic acid, vitamin В_с (pteroylglutamic acid).

В_с vitamin deficiency is rare, because folic acid is synthesized by the micro flora of the gastrointestinal tract and always enters the organism in sufficient quantity, but in the case of this vitamin deficiency anemia and disorders of the digestive organs can occur.

Folic acid, as a coenzyme of several enzymes, carries one-carbon fragments in the biosynthesis of many compounds: methyl group, oximethyl (-СН₂ОН), formyl.

Sources of folic acid are spinach, cauliflower, animal’s liver, bread. Particularly high content of it is in yeast.

Vitamin P (rutin). Currently, there are many compounds with P-vitamin activity. They are called bioflavonoids.

In the absence of vitamin P capillary permeability is increased, which is accompanied by bleeding, pain in the limbs, general weakness and fatigue. It is suggested that vitamins P are involved in redox reactions.

Source of vitamin P for a human are the same products, in which there are a lot of vitamin C, such as black currant and lemon.

Vitamin H (biotin). With a lack of this vitamin in humans there is inflammation of the skin, hair loss, increased allocation of fat by sebaceous glands of the skin (seborrhea). The mechanism of biotin action: as a coenzyme it is part of enzymes that increased the velocity of carboxylation reactions.

Source of vitamin H are the liver and kidneys of cattle, eggs, milk, tomatoes, soybeans, carrots, potatoes, peas. The intake of biotin in the organism is also possible from microbial symbionts.