How Vitamins Work

The history of the discovery of vitamins

The history of the discovery of vitamins goes far into past centuries. So, for example, scurvy for sailors was comparable to smallpox and plague - it did not spare anyone, without dividing by nation, age or position. In 1741, the world-famous Captain Bering, who first discovered the strait between Alaska and Chukotka, also fell from her. During the existence of the British fleet, more sailors died from this disease than in all the wars in which the island kingdom only took part.

For the first time, the English doctor James Lind distinguished himself by interrupting the endless series of deaths: he proposed in his work “A Treatise on Scurvy” to use lemon juice as methods of prevention and treatment. Although his experiments did not gain universal recognition, and he himself assumed that tissue rotting was the basis for the development of this disease, the use of citrus fruits saved the lives of all members of the crew of the ship on which he served. James Cook introduced cabbage, another source of vitamin C, to his team's diet, which also helped prevent scurvy outbreaks.

No less common was another disease - beriberi. Christian Aikman puzzled over her solution in his experiments with chickens. He observed an interesting picture: birds eating white, peeled rice quickly became susceptible to this pathology - and then he suggested the presence of a certain compound in the shell of this cereal - the very one that acted as a kind of antidote. It remained only to find the poison in the core of the rice - and to do this, given its complete absence there, was very difficult.

Nikolai Lunin went much further: observing how laboratory rats die when fed with synthetic mixtures containing all the food components that make up milk (that is, water, proteins, fats, carbohydrates), he eventually suggested that animals need more substances not discovered either by him or by other scientists - substances necessary to sustain life. His views laid the foundation for the doctrine of vitamins.

Perhaps Kazimierz Funk put the final touch: he isolated an organic compound from the shell of rice grains, which contributed to the cure of beriberi in very small concentrations of pigeons. He called it "vitamine" - that is, "vital amine".

Vitamins were discovered by scientists around the world until 1948 - the last to be discovered was the famous cyanocobalamin or B12. Although, who knows: maybe time will pass, and a new life-giving amine will be rediscovered by researchers and doctors.

What are vitamins

The importance of their intake with food lies in the function of these low molecular weight compounds: they act as a kind of assistants (coenzymes) in many enzymatic reactions.

It should be noted that, despite a certain amount of knowledge of their biochemical transformations, as well as their role and functions, the diagnosis of deficiencies is sometimes complicated by the fact that not all syndromes that occur with vitamin deficiency can be associated with its known properties: for example, Wernicke's encephalopathy, develops, like beriberi, with a deficiency of thiamine (B1).

The clinical picture also does not always remain clear and distinct - especially if the patient has multiple deficiencies that overlap each other like a semi-open fan.

In addition, there are often problems with their diagnosis - all because these organic compounds, as a rule, fulfill their role inside cells. Let's take, say, a fairly common analysis: determining the content of vitamin B12 in the blood serum - it is increasingly being taken not only by adherents of plant nutrition, but also by patients who are generally interested in their health. High or normal levels (even taking into account optimal values, and not laboratory references) of cyanocobalamin can often be accompanied by symptoms of anemia (or rather, one of its varieties - megaloblastic): all because it simply cannot go inside the cell.

Types of vitamins and their importance for the human body

All vitamins are divided depending on their solubility into water-soluble and fat-soluble - this classification has been used for decades, despite one significant drawback: as soon as science stepped forward, scientists learned how to synthesize water-soluble analogues for fat-soluble vitamins.

Water soluble vitamins include:

1. Thiamine - vitamin B1 or aneurin. Its coenzyme forms are involved in reactions and mechanisms that provide energy generation (such as, for example, the Krebs cycle), as well as provide building blocks for the synthesis of nucleic acids (B1 is necessary for the pentose phosphate pathway, which, among other things, is also one of the processes of utilization glucose).

   Its deficiency is accompanied by the development of beriberi (dry, wet or cerebral), as well as Korsakoff's psychosis, characterized by memory loss. There may be convulsions, burning feet, rapid pulse, and an increase in blood glucose levels is also characteristic.

2. Riboflavin (B2) is another representative of the B vitamins, necessary for:

   • energy production;

   • formation of keto acids from amino acids;

   • detoxification;

   • metabolism of uric acid and homocysteine.

   With a lack of B2, the main symptoms will be cracks on the outer surface of the lips and in the corners of the mouth; peeling of the skin; redness of the tongue; corneal vascularization. In addition, riboflavin deficiency has been linked to growth retardation, anemia, neurodegeneration, and even some types of cancer; it also exacerbates iron deficiency.

   It is noteworthy that the addition of B2 to lung cancer cell lines led to their increased division - this led scientists to speculate about its role in the progression of this pathology. On the other hand, B2 deficiency was associated with a decrease in hepatocellular carcinoma cell division.

   Study: Anti-Tumor Effects of Vitamin B2, B6 and B9 in Promonocytic Lymphoma Cells

3. Vitamin B3, PP or niacin - plays an important role in energy formation reactions and glucose utilization mechanisms. One of its coenzymatic forms (NADPH2) is necessary for the synthesis of steroid hormones, fatty acids, neutralization of toxins in the liver, maintaining the resistance of erythrocytes to hemolysis factors, leading to their destruction.

   It is noteworthy that the B3-based drug, which was used to treat mitochondrial myopathy in laboratory mice, effectively delayed the progression of the disease both at its early and later stages, causing the formation of mitochondria in skeletal muscle and brown adipose tissue, and also prevented the appearance of various abnormalities of these small organelles that act as energy powerhouses.

   Study: Effective treatment of mitochondrial myopathy by nicotinamide riboside, a vitamin B3

   Niacin deficiency is accompanied by the development of pellagra - a disease that includes three main "D": diarrhea, dementia, dermatitis. Sometimes a fourth is added - death (death).

4. Vitamin B6 (pyridoxine) - provides a number of vital reactions:

   • Production of neurotransmitters (adrenaline, norepinephrine, GABA, dopamine and serotonin) and histamine.

   • The formation of erythrocytes.

   • Synthesis of heme - one of the constituent parts of the hemoglobin molecule.

   • Metabolism of glucose and fats.

   • Conversion of the sulfur-containing amino acid cysteine ​​(formed from homocysteine).

   • Activation of vitamin B3.

    

   Pyridoxal phosphate (a bioactive form of vitamin B6) also has anti-cancer effects: for example, its addition has been associated with apoptosis (programmed death) of adenoma (pituitary tumor) cell lines in rats.

   Deficiency is accompanied by mental disorders, convulsions (resulting from a violation of the synthesis of gamma-aminobutyric acid, the main inhibitory mediator in the Central nervous system), the development of anemia, a high level of homocysteine, and the appearance of ulcers in the oral cavity.

5. Vitamin B9 - folic acid. Takes part in the synthesis of nucleic acids (DNA and RNA) by forming their building blocks; necessary for the implementation of methylation reactions (transfer of the CH3 group), which ensure the neutralization of the amino acid homocysteine, the inclusion of various genes, the synthesis of phospholipids and other biologically active molecules necessary for the body.

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   Its deficiency is accompanied by megaloblastic anemia (which is characterized by the circulation of large erythrocyte precursors in the blood) and hyperhomocysteinemia, one of the most significant markers of cardiovascular pathologies.

6. Vitamin B12 - cobalamin. It is necessary for the neutralization of homocysteine, the synthesis of nucleic acids, the formation of succinic acid - one of the key elements in the Krebs cycle, as well as for the synthesis of the myelin sheath of nerve fibers (a kind of insulating substance that promotes impulse transmission strictly along its road highway) and cell proliferation (division).

   It must be borne in mind that B12 (unlike the rest of the B vitamins) is able to accumulate in the liver - which is why its deficiency, even in strict vegetarians, may not develop immediately, but after several years (sometimes even decades).

   Symptoms of its deficiency may include:

   • An increase in homocysteine ​​levels, accompanied by an increased risk of strokes and heart disease, varicose veins and even glaucoma.

   • Neurological disorders - in particular, tingling in the extremities may be present.

   • Violation of heme formation and / or the development of pernicious anemia.

   • Characterized by a "polished" tongue.

7. Vitamin C or ascorbic acid - ensures the occurrence of hydroxylation reactions that contribute to:

   • The formation of collagen, one of the main proteins of connective tissue, and the maintenance of its normal structure.

   • Synthesis of bile components.

   • The production of carnitine - a carrier of fatty acids from the cytoplasm of the cell in the furnace of mitochondria, where they are burned to form energy.

   • Synthesis of norepinephrine - one of the main neurotransmitters of the Sympathetic nervous system.

Vitamin C is also necessary for the normal metabolism of iron - in particular, it retains it in its divalent form.

Ascorbic acid stimulates the activation and / or formation of cells of the immune system: T-lymphocytes and natural killers that resist pathogenic microorganisms and cancer cells.

In addition, injections of ascorbic acid are increasingly being used in the treatment of cancer. Although their effect in reducing tumor size is still controversial, 53% of the studied patients with bone metastases showed a significant improvement in pain symptoms.

In addition, scientists note that vitamin C can also act as a pro-oxidant, stimulating the formation of hydrogen peroxide and reactive oxygen species, which have a cytotoxic effect on cancer cells.

Deficiency of ascorbic acid is associated with increased bleeding due to vascular fragility in conditions of impaired structure of collagen fibers. There may be bruising, pain and swelling in the areas of the joints, a violation of the outflow of bile, and hair loss. With an acute deficiency, scurvy develops.

The group of fat-soluble vitamins includes:

1. Vitamin A (its derivatives: retinol, retinal, retinoic acid) - is part of the main visual pigment - rhodopsin, which provides twilight vision. Also involved in the production of erythrocytes and in the mechanisms of growth of epithelial tissue.

   It is noted that vitamin A reduces the production of pro-inflammatory mediators and other signaling molecules in fat cells, and its form, such as retinoic acid, can inhibit the differentiation of adipocyte precursors.

   Study: Vitamins and obesity

   Its insufficient intake is accompanied by a deterioration in night vision (up to more serious degenerative changes and the development of complete blindness), dry skin and its peeling, and impaired functioning of the immune system.

2. Vitamin E (tocopherol) is one of the best known and most powerful antioxidants in the human body. Protects cell membranes (and in particular, their constituent unsaturated fatty acids or their residues) from free radicals. In addition, tocopherol inhibits the adhesion of platelets - their adhesion to the damaged area with the formation of specific "plugs".

   Deficiency is accompanied by the destruction of red blood cells (hemolysis) and various neurological disorders - in particular, impaired coordination and damage to sensory nerves.

3. Vitamin K.

   Two types of vitamin K are known: K1 (phylloquinone), which stimulates blood clotting processes, and K2 (menaquinone), which acts on bone tissue, the vascular network, as well as the pancreas, kidneys, lungs and testicles by activating proteins dependent on it.

   The most common forms of vitamin K2 are MK-4 and MK-7, short and long chain molecules, respectively. A number of clinical studies have studied the impact of K2 MK-4 on the health of women with postmenopausal osteoporosis: for example, its intake at a concentration of 45 mg / day was associated with a reduced risk of hip and vertebral fractures.

   Study: Immunomodulatory effect of vitamin K2: Implications for bone health

   Deficiency is accompanied by increased bleeding (often from the nose and gums), and there may be blood in the stool.

4. Vitamin D or calciferol - promotes calcium absorption from the intestines, reduces its excretion, and also mobilizes this mineral from bone tissue. It is necessary to maintain the functions of the immune system, the synthesis and release of insulin, lowering blood pressure (by inhibiting renin function).

   In addition, vitamin D affects reproductive function - both in women and men - in particular, on the morphology of germ cells, maturation of follicles, the process of ovulation and implantation of the fetal egg. The binding of calciferol to receptors promotes the expression of the CYP19A1 gene, which encodes an enzyme such as aromatase (promotes the transformation of androgens into estrogens).

    

   Remarkably, more than 85% of women with polycystic ovary syndrome (PCOS) are deficient in vitamin D.

   A sufficient supply of this vitamin prevents, according to research, the development of prostate and breast cancer, as well as autoimmune diseases such as type 1 diabetes and rheumatoid arthritis.

   A relationship was also noted between the occurrence of endometriosis, another common gynecological disease, and vitamin D deficiency. In particular, the discovery in the endometrium of the uterus of receptors for vitamin D and the enzyme 1-alpha-hydroxylase, which is involved in the transformation of calciferol, contributed to the assumption of its possible formation in this region.

Deficiency leads to softening of the bones (osteomalacia), in children - to rickets, to weakness in the muscles.

Norms of consumption of vitamins

Consumption rates for each of the vitamins largely depend on age, gender, region of residence, working conditions, the presence of stress factors and concomitant diseases. They are very individual and should be selected based on your laboratory tests, complaints and objective as well as subjective symptoms by nutritionists. We have given below the basic daily requirements of the body.

1.  Vitamin B1: 1.5 mg.

   Thiamine is found in sunflower seeds (1.84 mg/100g), oat bran (1.17 mg/100g), peas (0.9 mg/100g), lentils (0.5 mg/100g) and hazelnuts (0.45 mg/100g).

2. Vitamin B2: 1.7 mg.

   We recommend adding the following foods to your diet: porcini mushrooms (2.45 mg/100g), beef liver (2.2 mg/100g), quail eggs (0.65 mg/100g), sesame seeds (0.35 mg/100g).

    

   If you are considering supplementation, the most metabolically active form of this vitamin is riboflavin-5-phosphate. In particular, it can be used in hypothyroidism, accompanied by a violation of this transformation, or in the presence of breakdowns of one or more genes of the folate cycle.

3. Vitamin B3: 20-30 mg.

   Niacin is found in tuna (15.5 mg/100g), wheat bran (13.5 mg/100g), rabbit and chicken meat (about 12 mg/100g), mushrooms (10.7 mg/100g), squid (7.5 mg/100g), buckwheat ( 7.2 mg/100g) and peas (7 mg/100g).

4. Vitamin B6: 2 mg.

   Pistachios (1.7 mg/100g), beans (0.9 mg/100g), walnuts (0.8 mg/100g), tuna (0.75 mg/100g), egg yolks (0.46 mg/100g) are rich in pyridoxine.

5. Folic acid: 0.4-0.5 mg.

   B9 in food is concentrated in: cod liver (110 mcg / 100g), avocado (89 mcg / 100g), Chinese cabbage (80 mcg / 100g), hazelnuts (69 mcg / 100g), broccoli (63 mcg / 100g), cilantro (60 mcg/100g).

6. Vitamin B12: 6 mcg.

   Cyanocobalamin is rich in beef liver (70 mcg/100 g), octopus (36 mcg/100 g), mackerel (19 mcg/100 g), red caviar (10 mcg/100 g).

7. Vitamin C: 60-70 mg.

   Found in rosehip (650mg/100g), sea buckthorn (200mg/100g), bell pepper (200mg/100g), kiwi (180mg/100g), parsley (150mg/100g), cauliflower (70mg/100g) ), orange (60 mg/100g), chanterelles (35 mg/100g).

    

   Given that the real champion in the content of ascorbic acid is rose hips (and not citrus fruits, as is commonly believed), we recommend that you compensate for vitamin C deficiency with its decoction. Grind the rose hips with a knife and pour (at the rate of 1 liter for every 50-60 grams) with water, after boiling it. Close the lid and leave to infuse for several hours.

8. Vitamin A: 5000 IU or 1500 mcg.

   It can be found in fish oil (25,000 mcg/100g), beef liver (8360 mcg/100g), carrots (2000 mcg/100g), eel (1200 mcg/100g), spinach (750 mcg/100g), dried apricots (580 mcg/100g).

9. Vitamin E: 30 IU.

   Found in sunflower oil (44 mg/100g), almonds (24 mg/100g), pine nuts (9 mg/100g), dried apricots (5.5 mg/100g), sea buckthorn (5 mg/100g), pistachios (3 mg/100g ).

10. Vitamin K: 0.2-0.3 mg.

    Concentrated in Parsley (1640mcg/100g), Spinach (480mcg/100g), Green Onions (165mcg/100g), Celery (40mcg/100g), Kiwifruit (40mcg/100g), Avocado (21mcg/100g) and blackberries (20 mcg/100g).

11. Vitamin D: 400 IU.

    Calciferol is rich in fish oil (250 mcg/100g), mackerel (16 mcg/100g), pink salmon (11 mcg/100g), egg yolks (7.7 mcg/100g), tuna (5.7 mcg/100g), flounder (2.8 mcg/100g). ), pike (2.5 µg/100g).

Myths about vitamins

1. All vitamins are useful - this is partly true. But taking them, as well as other biologically active additives, is indicated only under the condition of a laboratory-proven deficiency or a bright symptomatology accompanying their insufficiency. It must be remembered that these organic compounds largely ensure the flow of biochemical reactions - and in accordance with their concentration, the rate of metabolic processes will also change.

   In addition, fat-soluble vitamins, as well as B12, are capable of accumulation - and hypervitaminosis, that is, their excess content in the body, is no less unfavorable than hypovitaminosis. So “drink, it won’t be superfluous” we leave the pseudo specialists in social networks.

2. Vitamins don't have an expiration date - another common misconception. Look carefully at the box with dietary supplements - it will definitely indicate the date after which their intake is not recommended.

3. Vitamin D is synthesized enough if you are in the sun. Then why is there a shortage of it even in the sunniest countries?

   In addition, the following factors influence its formation process in the epidermis of the skin:

   • Use of sunscreens;

   • Clothes (and people, unfortunately or fortunately, do not run naked around equatorial Africa);

   • wavelength of sunlight;

   • Season;

   • The presence of pigmentation - so, melanin protects the skin from the penetration of ultraviolet rays.

4. Fruits make up for the lack of vitamins. The latter are indeed excellent sources of many nutrients, fiber and antioxidants. That's just, say, cyanocobalamin with them you will not get.

    

5. An overdose of vitamins is impossible - again, an erroneous opinion that can lead to very serious consequences. We will not tire of repeating: the dosage of vitamins and the course of treatment should be prescribed strictly by a nutritionist.

   So, fat-soluble vitamins are contraindicated to be taken on an ongoing basis - and all because of their ability to accumulate. For example, vitamin A hypervitaminosis is accompanied by the following toxic manifestations:

   • Nausea

   • Headache

   • Liver damage

   • Itchy skin

   • Congenital malformations in the fetus

6. With a balanced diet, the body does not need vitamins - unfortunately, but this is not always the case. It is also necessary to take into account genetic factors (such as polymorphisms in genes that affect biotransformation and absorption of vitamins), the region of residence, as well as the presence of chronic inflammation, organ malfunctions and triggers in the form of stress.

Hypovitaminosis, avitaminosis and hypervitaminosis

Subsequently, hypovitaminosis can flow into beriberi - a disease that occurs with an acute shortage over a long period of time of a certain vitamin.

These two concepts should not be confused, no matter how similar, at first glance, they may seem. Avitaminosis always leads to a serious pathology - such as, for example, scurvy, which develops in conditions of long-term vitamin C deficiency. Hypovitaminosis of ascorbic acid manifests itself much milder, accompanied by bleeding gums, bruises, and swelling in the joints.

The exact opposite of hypovitaminosis is hypervitaminosis - this disorder is accompanied by an excessive intake of vitamins in the body and the development of intoxication as a result. It can occur with a single intake of a high dosage of the vitamin or as a result of its regular intake in concentrations exceeding the norm.

So, let's say, if an overdose of vitamin C usually leads to diarrhea and other disorders of the gastrointestinal tract, then fat-soluble vitamins can have much more serious consequences. For example, vitamin D, despite its huge range of functions, can contribute to soft tissue calcification and the deposition of kidney stones, and vitamin E to hemorrhages due to impaired clotting processes.

How to avoid vitamin deficiency

Common causes of deficiency are often:

1. Lack of intake - both with food, and due to improperly selected concentrations of biologically active additives.

2. Violation of absorption and / or metabolism of a vitamin - as a rule, due to a disease of any organ of the digestive system. For example, gastritis, erosions and ulcers of the stomach, reduced production of hydrochloric acid, irradiation from the pyloric section (adjacent to the duodenum) of the stomach to its other parts of Helicobacter, decreased function of epithelial cells - all these factors inhibit the absorption of vitamin B12, contributing to the development of symptoms of its deficiency and associated diseases.

3. Increased body needs - occur during a period of rapid growth, during pregnancy and breastfeeding.

4. Increased loss of the vitamin - for example, the use of alcohol and caffeine is accompanied by increased excretion of thiamine.

A few rules that would help you in the treatment or prevention of deficiency conditions:

1. Do not stick to mono-diets (apple, rice and others) - your diet should be varied and include all the main classes of nutrients needed by the body.

2. Completely exclude certain foods or a group of foods only if there are medical indications - for example, carbohydrate-free diets, quite common in contexts of rapid weight loss, deprive you of the flavonoids contained in the same berries and fruits, which act as powerful antioxidants; fiber needed to stimulate intestinal motility and control blood glucose levels, as well as many vitamins and minerals.

3. Consider the presence of diseases, inflammation and other damage to your organs when taking dietary supplements - for example, with various kinds of violations of the integrity of the gastric mucosa, it is recommended to take vitamin B12 in sublingual form - this contributes to its entry directly into the blood. Think of it as a freeway crash that collapses into dead lines of stopped cars—you can wait a long time for traffic to resume, or you can take a detour. What is more rational and economical in terms of saving time resources and nerve cells?

    

4. Choose the forms of supplements based on your genetics - you can not argue with nature, as they say. You can’t argue, but to outwit is quite!

   Now, breakdowns in the so-called folate cycle involved in the formation of neurotransmitters are increasingly being diagnosed; nitric oxide, acting as the main vasodilator; as well as in the reactions of neutralization of the amino acid homocysteine. In particular, polymorphisms are observed in three main genes: MTHFR, MTR, MTRR - this also makes adjustments in the intake of dietary supplements. Such patients are recommended to use not just vitamin B12, but its most active form, methylcobalamin.

5. Take vitamin A, D, E, K supplements with fatty foods - this is due to the biochemical properties and nature of these compounds.

6. When taking fat-soluble vitamins, make sure that there is an adequate outflow of bile - cholestasis (its stagnation) due to helminthic invasion, the presence of stones, or for any other reason leads to a violation of their absorption.

1. Do not take vitamins (especially water-soluble vitamins) with coffee - this will impair their absorption.

2. Study the antagonism and synergy between vitamins and minerals - for example, cyanocobalamin is recommended to be taken separately from other B vitamins; and vitamins A and K - at different times from each other.

In addition, folic acid supplementation may partially mask the symptoms and manifestations of its cyanocobalamin deficiency, leading, subsequently, to even more adverse effects.

Multivitamin complexes: pros and cons

Vitamins, like any other biologically active compounds, are able to interact both with each other and with minerals, increasing or decreasing the rate of absorption of each other - this is why it is so important to pay attention to the composition (in particular, its balance) and dosage components that make up multivitamin or vitamin-mineral complexes. The manufacturer does not always care about the synergy of certain compounds.

Uncontrolled intake of supplements in high dosages is fraught with a number of side effects - and they do not end with allergies alone. In addition, the forms of vitamins in the composition of the complex are no less important - especially if there are factors that slow down or make it impossible to convert them into more active metabolites within the body itself.

In general, in a qualitative analysis, good multivitamin complexes are even recommended for use - especially if they contain certain cofactors for better absorption of a particular vitamin.