Everything you wanted to know about vitamins, but were afraid to ask
Vitamins (from Lat. Vita - "life" and amine) - a group of low molecular weight organic compounds of relatively simple structure and diverse chemical nature. This is a group of organic substances combined by chemical nature, united on the basis of their absolute necessity for a heterotrophic organism as an integral part of food. Autotrophic organisms also need vitamins, getting them either through synthesis, or from the environment. So, vitamins are part of nutrient media for growing phytoplankton organisms. Most vitamins are coenzymes or their precursors.
Vitamins are found in food (or in the environment) in very small quantities and therefore belong to micronutrients. Vitamins do not include trace elements and essential amino acids.
The science at the junction of biochemistry, food hygiene, pharmacology and some other medical and biological sciences, which studies the structure and mechanisms of action of vitamins, as well as their use in therapeutic and prophylactic purposes, is called vitaminology.
Vitamins - Wikipedia, the free encyclopedia.
Vitamins perform a catalytic function as part of the active centers of various enzymes, and can also participate in humoral regulation as exogenous prohormones and hormones. Despite the exceptional importance of vitamins in metabolism, they are neither a source of energy for the body (they do not have calories), nor structural components of tissues.
The concentration of vitamins in the tissues and the daily need for them are small, but with insufficient intake of vitamins in the body, characteristic and dangerous pathological changes occur.
Most vitamins are not synthesized in the human body, so they must be regularly and in sufficient quantities into the body with food or in the form of vitamin-mineral complexes and food additives. The exceptions are vitamin D, which is formed in human skin by ultraviolet light; Vitamin A, which can be synthesized from precursors entering the body with food; and niacin, the precursor of which is the amino acid tryptophan. In addition, vitamins K and B3 are usually synthesized in sufficient quantities by human bacterial microflora of the colon.
Three principal pathological states are associated with the violation of the intake of vitamins: the lack of a vitamin is vitamin deficiency, the lack of vitamin is hypovitaminosis, and the excess of vitamin is hypervitaminosis.
For 2012, 13 substances (or groups of substances) are recognized as vitamins. Several more substances, such as carnitine and inositol, are under consideration. Based on the solubility, the vitamins are divided into fat-soluble - A, D, E, K , and water-soluble - C and B vitamins . Fat-soluble vitamins accumulate in the body, and the place of their accumulation is adipose tissue and liver. Water-soluble vitamins are not stored in substantial quantities and are excreted with water in excess. This explains the high prevalence of hypovitaminosis of water-soluble vitamins and hypervitaminosis of fat-soluble vitamins.
Names and classification of vitamins
Vitamins are conventionally denoted by the letters of the Latin alphabet: A, B, C, D, E, H, K, etc. Later it turned out that some of them are not independent substances, but a complex of individual vitamins. For example, the B vitamins of group B are well studied. The names of the vitamins underwent changes as they were studied (data on this are given in the table).
The modern names of vitamins were adopted in 1956 by the Commission on the Nomenclature of the Biochemical Section of the International Union of Pure and Applied Chemistry.
For some vitamins, a certain similarity of physical properties and physiological action on the body has also been established.
So far, the classification of vitamins was based on their solubility in water or fats. Therefore, the first group consisted of water-soluble vitamins (C, P and the whole group B), and the second group - liposoluble vitamins - lipovitamins (A, D, E, K). However, as early as 1942–1943, Academician A.V. Palladin synthesized a water-soluble analogue of vitamin K, vikasol.
And recently received water-soluble drugs and other vitamins of this group. Thus, the division of vitamins into water and fat soluble to some extent loses its value.
|Letter designation|| Chemical name as per international nomenclature
(other names are in brackets)
(F - fat soluble
B - water soluble)
|Consequences of beriberi, physiological role||Upper tolerance level||Daily need|
| A 1
|| Retinol (axeroftol, antioxerophthalic vitamin)
|F||Night blindness, xerophthalmia||3000 mcg||900 (adults), 400-1000 (children) mcg ret. eq.|
|B 1||Thiamine (aneurin, antineuritic)||AT||Beriberi, Gaye syndrome - Wernicke||not installed||1.5 mg|
|B 2||Riboflavin||AT||Ariboflavinoz||not installed||1.8 mg|
|B 3 , PP||nicotinamide (nicotinic acid, niacinamide, anti-pellet vitamin)||AT||Pellagra||60 mg||20 mg|
|B 4||Choline||AT||Liver disorders||20 g||425-550 mg|
|B 5||Pantothenic acid (calcium pantothenate)||AT||Joint pain, hair loss, cramping of limbs, paralysis, impaired vision and memory.||not installed||5 mg|
|B 6||Pyridoxine (Adermin)||AT||Anemia, headaches, fatigue, dermatitis and other skin diseases, skin of a lemon-yellow color, disturbances of appetite, attention, memory, vascular function||25 mg||2 mg|
|B 7 , H||Biotin (antiseborrheic factor, factor W, skin factor, coenzyme R, factor X)||AT||Skin lesions, loss of appetite, nausea, swelling of the tongue, muscle pain, lethargy, depression||not installed||50 mcg|
|B 8||Inositol [# 1] (inositol, meso-inositol)||AT||No data||no data||no data [# 2]|
|B 9 , B s , M||Folic acid (folacin)||AT||Folic deficiency anemia, abnormalities in the development of the spinal tube in the embryo||1000 mcg||400 mcg|
|B 10||Para-aminobenzoic acid, PUB (n-Aminobenzoic acid)||AT||Stimulates the production of vitamins by intestinal microflora. Included in folic acid||Not installed|
|B 11 , B t||Levarnitine [# 1]||AT||Violations of metabolic processes||no data||300 mg|
|B 12||Cyanocobalamin (antianemic)||AT||Pernicious anemia||not installed||3 mcg|
|B 13||Orotic acid [# 1]||AT||Various skin diseases (eczema, neurodermatitis, ichthyosis)||no||0.5-1.5 mg|
|B 15||Pangamic acid [# 1]||AT||no data||50-150 mg|
|C||Ascorbic acid (anti-scaling (anti-scorching) vitamin||AT||Scurvy (Latin scorbutus - scurvy), bleeding gums, nosebleeds||2000 mg||90 mg|
| D 1
Ergocalciferol (calciferol, anti-anti-vitamin vitamin)
|F||Rickets, osteomalacia||50 mcg||10–15 mcg|
|E||tocopherols||F||Neuromuscular disorders: spinal-cerebellar ataxia (Friedreich's ataxia), myopathies. Anemia  .||300 mg current. eq.||15 mg current. eq.|
| K 1
|F||Hypocoagulation||not installed||120 mcg|
|N||Lipoic acid, Thioctic acid [# 1]||F||Necessary for normal functioning of the liver||75 mg||30 mg|
|P||Bioflavonoids, polyphenols [# 1]||AT||Capillary fragility||no data||no data|
|U|| Methionine [# 1]
S-methylmethionine sulfonium chloride
|AT||Antiulcer factor; vitamin U (from the Latin. ulcus - ulcer)|
As a rule, the daily rate of vitamins varies depending on age, occupation, season of the year, gender, pregnancy, and other factors.
Antivitamins - a group of organic compounds that suppress the biological activity of vitamins. These are compounds close to vitamins in chemical structure, but with opposite biological effects. When ingested, antivitamins are included instead of vitamins in metabolic reactions and inhibit or disrupt their normal course. This leads to vitamin deficiency, even in cases where the corresponding vitamin is supplied with food in sufficient quantities or is formed in the body itself. Antivitamins are known for almost all vitamins. For example, antivitamin of vitamin B1 (thiamine) is pyritiamine, which causes polyneuritis.
Multivitamin preparations - pharmacological preparations, containing in their composition a complex of vitamins and mineral compounds.
The only natural nutritional multivitamin is breast milk, which contains a valuable set of many essential vitamins. For the prevention of hypovitaminosis, especially in children, it is recommended to use complex vitamin preparations. Multivitamin preparations are used not only for the prevention and treatment of hypovitaminosis, but also in the complex therapy of eating disorders such as malnutrition or paratrophy.
A high level of metabolism in children, which not only supports vital activity, but also ensures the growth and development of the child’s body, requires an adequate and regular supply of not only vitamins, but also macro- and microelements. According to scientists, the use of vitamin-mineral complexes is very important for Russian children and teenagers.
At the same time, there is evidence of an increase in the risk of cancer and heart disease and a decrease in life expectancy with the additional intake of vitamins.
Decomposition of vitamins during cooking
Under the influence of environmental factors (temperature, oxygen, sunlight, acids, alkalis in the environment), vitamins are destroyed and lose their biological activity. According to the degree of sensitivity, different vitamins have different properties, some show high resistance, others quickly collapse. This is primarily due to the fact that vitamins, due to their chemical structure, are highly active compounds that easily enter into chemical reactions. From the moment the vitamin molecule was born naturally or by chemical synthesis, and up to the moment it enters the human or animal body, its fate depends largely on the conditions of storage and processing.
The main factors of instability of vitamins are:
- Air oxygen
- pH of the medium
- Metal ions (iron, copper)
|Vitamin||To the light||To oxidation||To recovery||To temperature||To metal ions||To humidity||Optimum pH|
|A||+++||+++||++||++||+||Neutral, slightly alkaline|
|D 3||+++||+++||++||++||++||Neutral, slightly alkaline|
|K 3||++||+||++||++||+++||++||Neutral, slightly alkaline|
|B 1||+||++||+++||+++||++||++||Weak acid|
|B 4||+++||Neutral, slightly acid|