Vitamin A (Retinol). How to take vitamin a correctly and what it is good for Vitamin a what it is prescribed for
Vitamins are an essential part for the proper functioning of the human body. Without these low molecular weight compounds, metabolism is impossible, as well as the work of immunity. A large amount of vitamins is found in vegetables and fruits, which is why they must be eaten regularly. In this article, we will look at vitamin a or retinol, which has a major impact on the functioning of the whole organism as a whole.
general characteristics
It is worth knowing that four chemicals are included in the composition of vitamin A. We are talking about retinol, dehydroretinol, retinoic acid and retinal. The first two elements are important for tissue repair and have a beneficial effect in the treatment of diseases associated with the genital organs. Retinal is important for vision, and retinoic acid for the epithelium. These are different forms of a given substance, so when we talk about it, we can mean either something specific or all together. But all four chemicals are united by one root “retinol”, which we will talk about in detail in this article. What is the use of vitamin A, and how to use it correctly without harming your health?
Benefit
As we have already said, without retinol, the proper functioning of our body is impossible. What is vitamin a good for?
- First, it is worth noting that this substance plays a huge role in vision, because the synthesis of the visual pigment rhodopsin is impossible without the presence of retinol in the body. Therefore, it is necessary for eye problems, such as: conjunctivitis, myopia, hyperopia,.
- It helps strengthen the immune system which means you will be less susceptible to viral infections.
- This substance is an excellent prevention of cancer.
- There is a constant renewal of cells, which promotes skin rejuvenation.
- In addition to the cosmetic effect, such as the elimination of wrinkles, retinol beneficially solves a number of skin problems: eczema, dermatitis, allergic reactions, furunculosis, seizures in the corners of the lips.
- This substance stimulates tissue repair (which is good for burns, open wounds, frostbite), and thanks to it, some hormones are synthesized.
- Retinol is good for hair condition, it actively helps with baldness. In addition, it has a positive effect on the nails (especially if your nails are constantly breaking and exfoliating). Healthy hair, skin and nails are something special.
- If you are concerned about thrush, swelling and other problems with the mucous membranes, then vitamin A can help get rid of these disorders.
- It is also prescribed for inflammation of the lungs, and in inflammatory processes in the liver and other organs.
- It is also an effective medicine. from problems with the gastrointestinal tract (from gastritis, for example).
Thus, the benefits of this substance for the body are obvious. But when buying retinol in a pharmacy, you should find out about all the contraindications before using it so as not to harm your health.
About contraindications
This drug is contraindicated if you have:
- Individual intolerance to a certain component.
- Beginning of pregnancy (first trimester).
- Cholelithiasis.
- Chronic pancreatitis.
- It is not advisable to combine this substance with tetracycline.
In general, retinol is well tolerated, but there are also patients who experience side effects. We are talking about drowsiness, weakness, headache, nausea and vomiting. As for childhood, there were observed: fever and intracranial pressure, as well as increased sweating, nausea with vomiting and allergic reactions. Most often, the symptoms will go away without the intervention of doctors, if the dose is reduced or the drug is completely canceled.
About drugs and use
Retinol is not only in products, therefore, if you have one, you will not be limited to one carrot. In pharmacies, you can buy retinol in completely different forms (depending on the purpose of use). So, you can buy:
- Solution for intramuscular injection.
- Solution for oral administration or use as an external medicine.
- Film-coated capsules with an oil solution of retinol inside.
- multivitamin complexes, which are not only in the form of capsules, but also in the form of powders or syrups.
There are a lot of preparations containing vitamin A in their composition, for example, it is in Alphabet, Aevit, Complivit, Duovit, Pikovit, Supradin. Naturally, the effect will be much more pronounced when this substance is taken orally or in injections than when applied externally. Otherwise, retinol affects only the upper layer of the skin, and its absorption in the body occurs in smaller quantities.
When purchasing vitamin a in one form or another, read its instructions so that there are no cases of overdose and hypervitaminosis.
- If you have avitaminosis, night blindness or diseases of the lungs or gastrointestinal tract, then the substance is administered intramuscularly and this is done in a hospital setting. As for the dosage, the injections are not made daily, but with a break of one day. In total, twenty to thirty injections are required. The maximum dose of one injection is fifteen mg, and thirty per day.
- Retinol is also useful for external use. They lubricate sores, frostbite, burns, wounds and other inflammatory processes on the skin. It is applied to the damaged area about five to six times a day, while tied with gauze. Most often, the treatment of skin diseases is not limited to local use, and the doctor prescribes vitamin A and internally for prevention.
- Inside vitamin a is useful for preventive purposes, three or five tablets are taken during the day. If this is a solution, then you need to take it drop by drop (from ten to twenty) three times a day after meals, you need to drip them on black bread. The course can take from two weeks to four months, depending on the degree of the problem and the purpose for which you are using retinol. As for the capsules, it is better to take them during a meal, so the gastric juice will be able to dissolve the gelatin shell more quickly, and the substance will work faster. To cure night blindness or skin diseases, it will be enough to take vitamin a inside for a month. It will also be useful in order to strengthen the immune system and maintain a balance of vitamins. After you complete the course, you must definitely take a break for two to three months, because retinol has a cumulative effect. If necessary, you can retake the course. Vitamin complexes should be taken only in order to avoid beriberi in cold periods of time, as well as to strengthen the immune system and make the body resistant to seasonal diseases. To treat certain diseases - this method will not work.
Vitamin A or retinol is best absorbed in combination with vitamin E. Therefore, most often vitamin E is prescribed in addition. Remember that no matter what the goal is, because of what you decide to use retinol, be sure to consult with a specialist first. We are talking here not only about intramuscular injection, but also about a simple addition to the cream. Even a harmless vitamin complex can cause, for example, an allergic reaction or other side effect. And in no case can serious diseases be treated on their own, competent consultation with a doctor is necessary. Remember that this is your health, and only a specialist can tell you how to take vitamin a correctly in order to avoid overdose and other negative consequences. Be healthy!
Vitamin A, or RETINOL in other words, was discovered by several scientists at the beginning of the twentieth century. It was almost the first vitamin that became known to mankind. It was designated "fat-soluble factor A", since it was not saponified under the influence of alkali. This is where the name "vitamin A" comes from. Scientists of those times were able to find out that the substance is associated with lipoids, helps animals grow. They also found out what contains vitamin A: butter, eggs and some dairy products.
Few people know that in addition to the second name - RETINOL - the vitamin has several other names: anti-infectious vitamin, antixerophthalmic, dehydroretinol.
The substance itself exists in two forms:
- ready-made form (actually vitamin A - RETINOL);
- provitamin A (carotene): a vegetable analogue of the vitamin, which already in the body becomes RETINOL.
Retinol is a pale yellow color that comes from a red plant pigment called beta-carotene. One of the advantages of the substance is its resistance to high temperatures. Therefore, after heat treatment, it will not lose most of its useful properties (only fifteen to thirty percent). True, if you store the product for a long time in the air, it will easily collapse.
Vitamin A properties
This substance can form the following compounds:
- RETINOIC ACID;
- RETINOL;
- RETINOLACETATE;
- RETINAL;
- RETINOL PALMITATE.
Vitamin A itself is an unsaturated cyclic alcohol. It is able to oxidize inside the body and form RETinoic acid and A-aldehyde in this way.
Already in past centuries, scientists have tried to find out where vitamin A can be contained. It turned out that its amount in animal products primarily depends on whether the animal itself consumed this vitamin. For this reason, this vitamin is much less in cow's oil than in fish oil, since fish feed on plant plankton rich in vitamin A.
Vitamin A (CAROTENE) is found in large quantities in foods:
- carrots;
- red rowan;
- parsley;
- pumpkin;
- sweet pepper;
- tomatoes;
- spinach;
- broccoli;
- green peas;
- green onions;
- peaches;
- apricots;
- apples;
- grapes;
- watermelons;
- melons;
- wild rose.
The listed products are sources of carotenoid, that is, vitamin A of plant origin.
There are also products of animal origin, which contain vitamin A (retinol) in large quantities:
- fish fat;
- liver (primarily beef);
- butter;
- eggs (especially yolks);
- cream;
- milk (whole);
Grain products, as well as skimmed milk (even with vitamin supplements) cannot be full-fledged sources of retinol, since they contain the substance in minimal concentrations.
The largest amount of vitamin A is found in the products below.
Table of foods high in vitamin A.
| Products | The amount of vitamin A in 100 g of product (mcg) | The content of the daily norm of vitamin in 100 g of the product (%) |
| Fish oil (from cod liver) | 25,000 mcg | 2500 % |
| Beef liver | 8,367 mcg | 836 % |
| Cod liver (canned) | 4400 mcg | 440 % |
| Carrot | 2000 mcg | 200 % |
| red rowan | 1500 mcg | 150 % |
| Acne | 1200 mcg | 120 % |
| parsley | 950 mcg | 95 % |
| Chicken egg yolk | 920 mcg | 92 % |
What is Vitamin A for?
Vitamin A plays an important role in the body. It helps to keep intact the cells that form the mucous membranes and skin, promotes the rapid healing of wounds, scratches and other injuries. It also prevents early keratinization and death of skin cells. Therefore, many cosmetics manufacturers include it or similar substances in their products.
Retinol- This is one of the most essential vitamins for the eyes. After all, it plays a significant role in the process of photoreception: it provides the possibility of clear twilight, color and light vision.
At the same time, this vitamin is a powerful antioxidant, so they are effective in the treatment and prevention of cancer.
Daily intake of vitamin A
To determine how much vitamin A the body needs, it is necessary to pay attention to the age and condition of the person. In children, men, women (especially pregnant and lactating), this figure will be different.
In children, the consumption rate will vary depending on age:
- infants from birth to six months need 400 mcg per day;
- after six months and up to a year - 500 mcg per day;
- from one to three years - 300 mcg;
- from four to eight years - 400 mcg;
- from nine to thirteen years - 600 mcg.
The male population requires 900 micrograms of retinol (or 3,000 IU) from 14 to 70 years of age.
Among women daily rate less: from 14 to 70 years old - 700 mcg (or 2,300 IU). But at the same time, the indicator changes during pregnancy or breastfeeding:
- pregnant women under 19 require 750 mcg;
- pregnant women over 19 - 770 mcg;
- lactating women under 19 years old - 1200 mcg;
- lactating mothers over 19 years old - 1300 mcg.
If a person is diagnosed with a disease associated with a lack of vitamin A, then the dose is often increased to 10 thousand IU per day.
Often unable to meet daily allowance vitamin A only through food. Therefore, a third of the daily allowance can be obtained from pharmacy supplements, and two-thirds from natural products.
Vitamin A deficiency: symptoms
Vitamin A deficiency can be expressed in the body in different ways: it all depends on the stage and severity of the condition. Signs can be expressed for a long time, appearing in turn.
There are 3 stages in the development of beriberi associated with vitamin A.
- primary stage. The functioning of some internal organs or systems may be disrupted. But this is not expressed clearly. A person feels tired, his working capacity decreases, the body loses its tone, and gets sick more often. Only laboratory tests will help to establish the cause and identify vitamin deficiency at this stage.
- Secondary stage. Clinically, you can establish a lack of elements. A person is exposed to a disease associated with a weakened immune system.
- Third stage. There is a complete deficiency of the vitamin, the ability of its absorption into the body is impaired. There are diseases associated with the lack of the required amount of retinol. Their treatment begins only after the restoration of the required amount of vitamin in the body.
Vitamin A - symptoms of hypovitaminosis:
- wrinkles appear early, the skin ages quickly, dandruff forms;
- "night blindness" - a person does not see well when it gets dark;
- the skin becomes dry, the skin is covered with acne;
- the condition of the teeth worsens;
- interrupted sleep, insomnia;
- tendency to apathy, fatigue;
- mucus and crusts accumulate in the corners of the eyes;
- reproductive disorders in men and women;
- the occurrence of foci of infections in the intestine;
- the appearance of a cyst in the liver;
- increased risk of pancreatic cancer.
Vitamin A deficiency in children is caused by the following conditions:
- decreased immunity;
- slow growth;
- fatigue;
- pale and dry skin;
- color blindness;
- chicken blindness.
In women, a lack of retinol leads to the development of mastopathy, cervical erosion, in men, erection and libido are lost, and urinary incontinence is possible. Sometimes, with a lack of this element, the development of lung cancer, pneumonia, bronchitis, and sinusitis is also possible.
Therefore, with any of these symptoms, you should immediately contact doctor to eliminate vitamin deficiency, as this is much easier to do than to treat a serious illness.
How to treat vitamin A deficiency?
With its deficiency, it is necessary to start treatment on time in order to prevent serious pathologies in the body from developing. First of all, the doctor prescribes therapeutic procedures to make up for his deficiency. Vitamin deficiency is treated in the following ways.
- Eliminate nutritional deficiencies. It is regulated, it becomes balanced. Be sure to eat foods high in carotene and retinol.
- Vitamin A preparations are prescribed. They will help eliminate beriberi in a few weeks. It is impossible to choose the medicine yourself, since it is prescribed taking into account the stage of hypovitaminosis and the patient's condition.
- Treatment of comorbidities. The lack of an element can be the cause of many diseases, up to the formation of tumors. It is for this reason that it is worth immediately starting treatment at the first symptoms.
Vitamin A: which is better to take?
Naturally, the most best vitamin A - the one that enters the body as part of natural products. But it is impossible to eat so much food for an ordinary person, because some of the elements have to be obtained from vitamin complexes.
Preparations with this element are presented as capsules (one and a half milligrams each), dragees (1 milligram each), oil solutions (for injection and oral administration), as well as retinol concentrates as part of fish oil.
Usually, drugs of chemical origin are rarely prescribed by a doctor, only in cases where the patient does not have the opportunity to eat well. In other situations, it is advised to deal with an undesirable condition with the help of an appropriate diets.
Vitamin A analysis
Blood for vitamin A should be taken in almost the same way as for others. The analysis determines the content of retinol, the primary form vitamin A A.
Blood is taken from a vein, measurements are carried out using high performance liquid chromatography-mass spectrometry (HPLC-MS).
Before taking a blood test for vitamin A, you can not eat for at least two hours, but it is allowed to drink water without gas, additives and sweeteners. Smoking is prohibited half an hour before the tests.
This kind of study is prescribed for night blindness and pathologies that prevent the absorption of nutrients in the intestines. It is also often prescribed to determine the level of toxicity caused by excessive intake of vitamin A.
Normal is the amount of vitamin in the blood, equal to 0.3 - 0.8 mcg / ml. This means that there is enough vitamin in the body at the time of blood sampling. A lower level of retinol indicates the depletion of the body's resources. Elevated levels indicate that the body cannot store more vitamin A, and its excesses are in the blood and accumulate in various tissues of the body, thereby poisoning them.
Vitamin A for children
Parents are often interested in “which vitamins contain vitamin A” and which drug is better to give to a child for prevention.
Often drugs in pharmacies contain only vitamin A or its combination with vitamin E. They can be taken only after the diagnosis of hypovitaminosis A, therefore they cannot be taken on their own.
Vitamin A: what to take for prevention
On their own, parents can give their baby vitamin A preparations only as part of multivitamin complexes, which can be taken to prevent hypovitaminosis of various substances. In them, usually the dose of vitamin A is such that there can be no overdose, as well as a shortage of the substance. Vitamin A can be bought in pharmacies in multivitamin complexes "Multi tabs", "Jungle", "Pikovit", "Complivit" and some others.
What vitamin A can you buy for a child? An excellent choice would be preparations with beta-carotene, as it will turn into retinol in the baby's body. But its advantage is that an overdose of beta-carotene is not dangerous for children - their skin color will simply change. The original color will return quickly after discontinuation of the drug. The Vetoron preparations (this is vitamin A in drops), the Alfavit complex and the Supradin Kids gel are very successful.
Forms of release of the drug for children are different. Vitamin A supplements for children come in a variety of forms. For the smallest children, it is very convenient to use drops, and multivitamin capsules are given to children over 7 years old, since they should be swallowed.
Most in demand in childhood There are sweet options for vitamin A supplements, such as delicious gel, multivitamin syrup, or chewable tablets.
Indications
Multivitamins, including retinol or provitamin A, are prescribed:
With a decrease in the content of vitamins and beta-carotene in food (this is observed in winter and in spring).
With an imbalance in the child's diet (especially if the menu is low in fat and protein).
In diseases of the gastrointestinal tract that impair the absorption of vitamins (colitis, hepatitis, peptic ulcer, pancreatitis, and others).
With increased stress on the child's body, for example, when playing sports.
The use of the drug "Aevit", retinol in capsules or in solution is indicated only for beriberi A. The use of an oily solution of carotene as a lotion is in demand for burns, heavily healing wounds, ulcers, eczema and other skin problems, as well as stomatitis.
In some cases, in particular on vitamin preparations, the vitamin content is written in IU - international units. In IU, the so-called "biological activity" is measured. 1 IU = 0.3 µg of vitamin A, or 0.6 µg of B-carotene. The average daily recommended intake of vitamin A = 1000mcg (1mg), or 3300 IU.
Table of vitamin A content in foodstuffs in mg/100g of the product, and as a percentage of the recommended average daily intake of 1000mcg (1mg).
| Products | Vitamin A content in mg/100g | The content of vitamin A in% to the average daily rate of 1 mg (1000 mcg) | |
| Fish fat | 19 | 1900 | 5,3 |
| chicken liver | 12 | 1200 | 8,3 |
| beef liver | 8,2 | 820 | 12,2 |
| Cod liver | 4,4 | 440 | 22,7 |
| Lamb liver | 3,6 | 360 | 27,8 |
| Pork liver | 3,4 | 340 | 29,4 |
| Beluga caviar granular | 1,0 | 100 | 100 |
| Acne | 0,9 | 90 | 111 |
| Quail eggs | 0,5 | 50 | 200 |
| Butter unsalted | 0,5 | 50 | 200 |
| Caviar caviar granular | 0,45 | 45 | 222 |
| chicken eggs | 0,35 | 35 | 285 |
| Dry cream | 0,35 | 35 | 285 |
| Cheese "Cheddar" | 0,3 | 30 | 333 |
| Cheese "Russian" | 0,26 | 26 | 385 |
| Roquefort cheese | 0,25 | 25 | 400 |
| Cream 35% | 0,25 | 25 | 400 |
| Sour cream 30% | 0,23 | 23 | 435 |
| beef heart | 0,23 | 23 | 435 |
| Beef kidneys | 0,23 | 23 | 435 |
| Cheese "Poshekhonsky" | 0,23 | 23 | 435 |
| Cheese "Dutch" | 0,2 | 20 | 500 |
| Sprats in oil | 0,15 | 15 | 667 |
| Processed cheese | 0,15 | 15 | 667 |
| Cheese "Brynza" | 0,12 | 12 | 833 |
| Fat cottage cheese | 0,10 | 10 | 1000 |
| Chicken | 0,09 | 9 | 1110 |
As a constant source of vitamin A, it is much better to use its provitamin - carotene, which is found in plant foods.
Firstly:
consuming with plant products, carotene accumulates in the human liver, and then, as needed, retinol is synthesized from it. This eliminates the possibility of hypervitaminosis - an excess of vitamin A in the human body with all the negative consequences.
Secondly:
To measure the content of vitamin A in foods, the IU (international unit) is used, which is equivalent to 0.3 micrograms of retinol, or 0.6 micrograms of B-carotene.
What contains B (beta) carotene (about vitamin A). Table.
| Product | Carotene content: mg/100 gr. product | Carotene content: in % of the average daily recommended rate. | In parentheses, the amount of the product containing the daily allowance, in grams. |
| red carrot | 12 | 600 | 17 |
| Red pepper | 10 | 500 | 20 |
| Parsley | 9 | 450 | 20 |
| Sorrel | 8 | 400 | 25 |
| Spinach | 8 | 400 | 25 |
| Rosehip dry | 6,5 | 325 | 30 |
| Green onion | 6 | 300 | 35 |
| Soya | 6 | 300 | 35 |
| Cheremsha | 4,2 | 210 | 50 |
| Salad | 3 | 150 | 65 |
| Rosehip fresh | 2,6 | 130 | 75 |
| viburnum | 2,5 | 125 | 80 |
| Prunes | 2,0 | 100 | 100 |
| ground tomatoes | 2,0 | 100 | 100 |
| Rowan garden | 1,8 | 90 | 110 |
| apricots | 1,6 | 80 | 125 |
| Pumpkin | 1,5 | 75 | 135 |
| Sea buckthorn | 1,5 | 75 | 135 |
| Dill | 1,4 | 70 | 140 |
| Rowan chokeberry | 1,2 | 60 | 165 |
| yellow carrot | 1,1 | 55 | 180 |
| Sweet green pepper | 1,0 | 50 | 200 |
| Peas | 0,8 | 40 | 250 |
| Chanterelles | 0,8 | 40 | 250 |
| Peaches | 0,7 | 35 | 285 |
| White cabbage | 0,6 | 30 | 335 |
| Melon | 0,4 | 20 | 500 |
| Brussels sprouts | 0,3 | 15 | 670 |
| Plum | 0,3 | 15 | 670 |
| Blackberry | 0,3 | 15 | 670 |
| Sweet potato | 0,3 | 15 | 670 |
| sea kale | 0,2 | 10 | 1000 |
| Raspberries | 0,2 | 10 | 1000 |
| Red currants | 0,2 | 10 | 1000 |
| Black currant | 0,1 | 5 | 2000 |
| red cabbage | 0,1 | 5 | 2000 |
| kohlrabi cabbage | 0,1 | 5 | 2000 |
| Watermelon | 0,1 | 5 | 2000 |
| cucumbers | 0,06 | 3 | 3350 |
It is necessary to use products containing carotene with the addition of oil, for better absorption, since vitamin A is fat-soluble.
Importance of vitamin A content in foods.
- enzymes necessary for the formation of connective tissue, bones, cartilage; also hyaluronic acid - the main intercellular substance.
- liver enzymes;
- taurine - is involved in the transmission of nerve impulses, has an anti-calcium effect (deposited on the walls of blood vessels);
- synthesis of proteins in muscle tissue;
– synthesis of DNA, RNA, collagen molecules;
- glycoproteins that are part of the intercellular membranes;
- sex hormones;
- formation of the immune system;
– enzymes that prevent premature aging of the skin;
- an enzyme in the retina involved in "twilight vision".
- growth, formation of skin and bone tissue, retina;
- reproduction processes;
In addition, due to its structure, this vitamin interacts with free radicals, that is, it has an antioxidant effect, and also enhances the antioxidant effect of vitamin E. This fact emphasizes the importance of the vitamin A content in food.
Deficiency (hypovitaminosis and beriberi) of vitamin A.
The earliest symptom of vitamin deficiency is reduced adaptation to low light. Or "night blindness". Various lesions of the skin (dermatitis), the intestinal mucosa (before the formation of ulcers), the genitourinary system (infection), bronchitis may begin to appear. Eye diseases associated with a decrease in tearing (wetting the eye). Decreased immunity, inhibition of reproductive function. Growth retardation in children. All these negative factors affecting the human body are due to a lack of vitamin A in food. This vitamin is most needed for pregnant and lactating women.
Too much vitamin A
This vitamin belongs to the group of fat-soluble, and therefore, unlike water-soluble, can accumulate in the body. This should be remembered by those who regularly use synthetic vitamins and fortified dietary supplements. Daily intake of vitamin in the amount of 4000 IU per 1 kg of body weight, for a period of six months to 12-15 months, causes chronic poisoning. In this case, the following symptoms appear: inflammation of the cornea of \u200b\u200bthe eyes, enlarged liver, nausea, pain in the joints is possible. An excess of the vitamin can cause brittle bones. This highlights the importance of taking into account the content of vitamin A in food, especially in dietary supplements consumed by humans.
Daily requirement of vitamin A.
The daily requirement for vitamin A ranges from 400 micrograms in childhood to 1500 micrograms for lactating women. Adolescents from 9 to 13 years old are recommended about 700 micrograms, adults - about 1000 micrograms of vitamin per day.
Vitamin A is involved in various metabolic processes and functions of the body, it strengthens the immune system and improves vision. This microelement is necessary for hair growth, improves the condition of the skin, and with its deficiency, the body is weakened up to the development of serious diseases. It is only necessary to decide what vitamin A is useful for and what products contain this useful component.
Vitamin A is considered the main source of healthy immunity and human beauty. This chemical compound, called retinol, is the main component of most tissues in the body and controls the processes of cell renewal and growth. It has been established that vitamin A is the building material of the human body, is involved in the synthesis of proteins, maintaining the correct metabolic process.
This complex compound can exist in two forms: vitamin A itself and the active form of beta-carotene, which is processed in the body into useful compounds. This component was discovered in 1913, and later scientists managed to isolate the active substance, called the liquid soluble factor A. Doctors have established why vitamin A is useful for women who need retinol to normalize the menstrual cycle. Subsequently, numerous carotenoids were found that are broken down in our body and become useful compounds.
The unique ability of this vitamin is that it can accumulate in the human body and subsequently consumed as needed. This almost completely eliminates the possible overdose of vitamins, ensures the proper functioning of a person, a strong immune system and proper cell regeneration.
Sources of Vitamin A
Many foods contain vitamin A, so providing the body with this healthy component is not difficult. Especially a lot of retinol in vegetables and fruits.
The following vegetables contain carotene:
- sweet potato;
- potato;
- Jerusalem artichoke;
- beet;
- garlic;
- tomatoes;
- pumpkin;
- carrot.
Especially a lot of carotene is found in fruits and vegetables that are yellow-orange or orange. This is because retinol is a natural plant pigment that gives vegetables such a cheerful color. Of the fruits, vitamin A is most found in tangerines, oranges and apricots.
It has been established that a large amount of this vitamin is found in foods that are made from cow's milk. Therefore, it is mandatory to include sour cream, cream, various cheeses, butter and full fat milk in the diet. Retinol is preserved even after heat treatment, which allows you to save this useful trace element for a long time in cheeses and other food products.
Today, on sale in pharmacies, you can find various mineral-vitamin complexes in capsules that contain retinol in an easily digestible form. At the same time, it is important to combine both beta-carotene of natural origin, which is found in vegetables and fruits, and the intake of special complexes that have a balanced composition, which positively affects the state of the human immune system. It is only necessary to study the instructions for specific supplements and take them only after consulting a specialist who will tell you how and why to take vitamin A.
Increased absorption of retinol
When you include a large amount of this vitamin in your diet, you need to remember that you need to eat such foods in combination with saturated fats. Therefore, if a salad is made from greens, vegetables and fruits, then it should be seasoned with high-quality sour cream or unrefined oil. Pumpkin or carrot juice, which will contain high amounts of beta-carotene, should be drunk with a little olive oil or heavy cream.
If vitamin A is well preserved after heat treatment, then prolonged cooking, stewing or frying foods that contain beta-carotene can reduce its amount in vegetables and fruits by about 35%. Nutritionists note that short-term heat treatment of retinol-containing products will be justified, as this allows you to destroy the cellulose hard shell of plants, which increases the absorption of this vitamin.
You can also grind vegetables and fruits on a grater, make juice from them, which at the same time improves the digestibility of products, prevents the loss of various kinds of vitamins during their heat treatment. It has been established that most retinol will be contained in freshly picked vegetables, but during long-term storage, especially when exposed to direct sunlight, this trace element is destroyed. Therefore, vegetables and fruits or juices should be consumed immediately after they are prepared, rather than waiting 20-30 minutes, which impairs their effectiveness and health benefits.
In recent years, there has been a tendency for animals destined for slaughter for meat or milk production to be fed with various additives and growth enhancers, which significantly reduces the vitamin content of such foods. Ideally, you need to grow vegetables and fruits yourself without the use of pesticides, which ensures their environmental friendliness and health benefits. If this is not possible, then you should still try to purchase such products from farmers with a proven track record who do not use powerful fertilizers to increase the yield of beds.
Beneficial features
Retinol is a strong antioxidant, it helps the body cope with harmful free radicals that constantly attack healthy cells, causing them to mutate, and ultimately - the development of serious and dangerous diseases. It has been established that this substance is the building material of human cells, therefore it is especially necessary for the proper development of the body. It is important to provide the required amount for young children who are just beginning to develop their skeleton and muscle mass.
For children, this vitamin is valuable because it is involved in metabolism, that is, bone tissue regeneration, strengthening and restoring the growing skeleton. For various kinds of injuries and fractures, doctors specifically prescribe mineral complexes with retinol or recommend eating vegetables and fruits that contain this vitamin.
Beta-carotene has a positive effect on the state of vision, but its lack causes a disease such as night blindness. Studies have shown that retinol enters the retina of the eye, transforms into the retinal component, which is involved in the formation of pigments necessary for vision. Regular intake of foods that contain a large amount of vitamin A will be an excellent prevention of the development of glaucoma and slow down the formation of cataracts.
Retinol is actively involved in the process of hematopoiesis, forming white blood cells. These elements are responsible for the production of white blood cells. It is extremely important to provide the body with the necessary amount of beta-carotene during pregnancy, since at this time the internal organs of the child and its skeletal system are laid, and a lack of vitamins can adversely affect the future health of the baby.
In the past, it was believed that only vitamin C was needed to strengthen the immune system. However, studies have shown that retinol plays an important role in the protective functions of the body, which activates white blood cells to suppress pathogenic bacteria. Therefore, it is extremely important to make a supply of it in the summer in order to successfully resist beriberi and various infectious and colds in autumn and winter.
The importance of vitamin A for the proper functioning of the heart and the prevention of various cardiovascular diseases has been established. Retinol promotes the production of good cholesterol in the body, which improves the condition of arteries and veins, prevents the appearance of plaques and blood clots.
Consequences of beriberi
The modern frantic rhythm of life leads to the fact that we do not eat properly, the necessary amount of microelements and vitamins does not enter the body, which leads to general weakness, problems with the immune system and the development of various kinds of dangerous diseases. Most often, such beriberi occurs in late autumn and winter, when there is a minimum of fresh vegetables and fruits in the diet.
Lack of beta-carotene in the body can lead to the following unpleasant consequences:
- weakening of the immune system;
- rapid aging of the skin;
- the appearance of acne;
- increased sensitivity of the teeth;
- problems with the perception of the yellow and blue spectrum;
- development of conjunctivitis and night blindness;
- the appearance of dandruff;
- menstrual disorders in women.
It has been established that the daily norm for a healthy person will be 800 mcg for women, and 1000 mcg for men. Infants should get at least 400 micrograms daily, and children under 10 years old should get 450 micrograms of this nutrient. During pregnancy, the body's need for retinol increases, so you should eat up to 1200 micrograms of beta-carotene daily. Accordingly, taking into account such recommended norms, it is possible to correctly develop a diet that will contain the necessary vitamins, strengthening our body and being an excellent prevention of various dangerous diseases.
In rare cases, an overdose of vitamin A can occur, leading to various side effects, including gait disturbance and dizziness.
Signs of an overdose of retinol include the following:
- increased fatigue;
- pain in the arms and legs;
- Strong headache;
- increased drowsiness;
- itching and redness of the skin;
- vomiting and nausea;
- decreased appetite.
When such symptoms appear, vegetables and fruits, fatty dairy foods should be excluded from the diet. If side effects persist for several days and do not go away on their own, you should seek medical help. In such a case, drugs are prescribed that normalize the well-being of patients. Such an overdose of vitamin A is especially harmful for children and pregnant women. Therefore, they should strictly follow a diet, do not uncontrollably eat foods rich in retinol.
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Good day, dear visitors of the project “Good IS! ", section" "!
In today's article I will tell you about such a useful and necessary vitamin for a person as Vitamin A and its importance in our daily life. So…
Vitamin A , he is "Retinol" - fat-soluble, antioxidant, necessary for good vision, bones, healthy skin, hair, as well as the functioning of the immune system.
Vitamin A received its name due to the fact that it was discovered by the first of the vitamin group, in 1913, by two independent groups of scientists (McCollut - Davis and Osborne).
Vitamin A participates in redox processes, regulation of protein synthesis, contributes to normal metabolism, the function of cell and subcellular membranes, plays an important role in the formation of bones and teeth, as well as body fat. Necessary for the growth of new cells, slows down the aging process. Vitamin A has a pale yellow color that comes from the red plant pigment beta-carotene.
Retinol does not dissolve in water, because. it is fat soluble, so it requires fats as well as minerals to be absorbed by the alimentary tract. Vitamin A stores remain in the body long enough to not be replenished every day.
There are two forms of this vitamin:
- ready-made vitamin A (retinol);
- provitamin A (carotene), which in the human body turns into vitamin A, so it can be considered a plant form of vitamin A.
Vitamin A is involved in redox processes, regulation of protein synthesis, contributes to normal metabolism, the function of cell and subcellular membranes, plays an important 
role in the formation of bones and teeth, as well as body fat; necessary for the growth of new cells, slows down the aging process.
Vitamin A supports night vision by producing a pigment called rhodopsin that can detect minimal light which is very important for night vision. It also helps to moisturize the eyes, especially the corners, preventing them from drying out and subsequent injury to the cornea.
Vitamin A is essential for the normal functioning of the immune system and is an integral part of the infection-fighting process. The use of retinol increases the barrier function of the mucous membranes, increases the phagocytic activity of leukocytes and other factors of non-specific immunity. Vitamin A protects against, and infections of the respiratory tract, digestive tract, and urinary tract. The presence of vitamin A in the blood is one of the main factors responsible for the fact that children in more developed countries are much easier to tolerate such infectious diseases as, while in countries with low living standards, mortality from these "harmless" viral infections is much higher. Vitamin A sufficiency prolongs life even for AIDS patients.
Retinol is essential for maintaining and restoring the epithelial tissues that make up the skin and mucous membranes. No wonder almost all modern cosmetics contain retinoids - its synthetic counterparts. Indeed, vitamin A is used in the treatment of almost all skin diseases (pimples, etc.). Skin injuries (wounds, sunburn) vitamin A accelerates the healing process, and also stimulates collagen synthesis, improves the quality of newly formed tissue and reduces the risk of infections.
Due to its close relationship with mucous membranes and epithelial cells, vitamin A has a beneficial effect on the functioning of the lungs, and is also a worthwhile addition in the treatment of certain diseases of the gastrointestinal tract (ulcers,).
Retinol is essential for normal embryonic development, feeding the fetus and reducing the risk of pregnancy complications such as low birth weight.
Vitamin A is involved in the synthesis of steroid hormones (including progesterone), spermatogenesis, and is an antagonist of thyroxine, a thyroid hormone.
Both vitamin A and β-carotene (beta-carotene), being powerful antioxidants, are means of prevention and treatment, in particular, preventing the reappearance of the tumor after surgery.
Both vitamin A and β-carotene protect brain cell membranes from the damaging effects of free radicals, while β-carotene neutralizes the most dangerous types of free radicals: polyunsaturated acid radicals and oxygen radicals.
The antioxidant effect of β-carotene plays an important role in the prevention of heart and arterial diseases, it has a protective effect in patients, and also increases the blood levels of “good” cholesterol (HDL).
Lutein and zeaxentin are the main carotenoids that protect our eyes: they contribute to the prevention and also reduce the risk of degeneration. yellow spot(the most important organ of vision), which in every third case is the cause of blindness.
Another carotenoid, lycopene (found mainly in tomatoes), protects against by preventing the oxidation and accumulation of low-density cholesterol on the walls of the arteries. In addition, it is the most "strong" carotenoid in terms of protection against cancer, especially breast, endometrial and prostate cancer.
- for adults 800-1000 mcg;
- for pregnant women 1000-1200 mcg;
- for nursing mothers 1200-1400 mcg;
- for children, depending on age and gender, 400-1000 mcg.
In diseases associated with retinol deficiency, the dosage can be increased to the upper allowable consumption threshold - 3000 mcg.
It should be noted that hard work, illness or require a sharp increase in vitamin A in the diet - however, the same can be said about many vitamins and. Climatic conditions also matter: in a temperate or even cold climate, it is not necessary to increase the norms of vitamin A, but in a hot, sunny climate it is needed much more, so those who like to relax in warm countries should carefully monitor their diet.
It is known that vitamin A accumulates in the liver, but its reserves there are drastically reduced after a procedure such as an X-ray examination.
Vitamin A deficiency symptoms
- dry skin, the appearance of wrinkles;
- increased sensitivity of tooth enamel;
- decreased immunity;
— ;
- weakened erection;
— ;
- exhaustion;
- respiratory infections;
- deterioration of vision;
- poor night vision (night blindness);
- dry conjunctiva of the eye;
- growth disorders in children.
Symptoms of an overdose of vitamin A
- bleeding gums;
— ;
— ;
- dry skin;
— ;
— ;
- in pregnant women, spontaneous abortions and fetal malformations are possible.
Vegetable: Green and yellow vegetables (carrots, pumpkin, sweet peppers, spinach, broccoli, green onions, parsley), legumes (soybeans, peas), peaches, apricots, apples, grapes, watermelon, melon, sea buckthorn, cherries; herbs (alfalfa, borage leaves, burdock root, cayenne pepper, fennel, hops, horsetail, kelp, lemongrass, mullein, oats, parsley, raspberry leaves, clover, bearberry, violet leaves, sorrel).
Animals: Fish oil, liver (especially beef), caviar, milk, butter, margarine, sour cream, cottage cheese, cheese, egg yolk.
Synthesis in the body: Formed as a result of oxidative cleavage of β-carotene.
The best sources of vitamin A are fish oil and liver, followed by butter, egg yolk, cream and whole milk. Cereal products and skim milk, even with vitamin supplements, are unsatisfactory sources, as is beef, which contains negligible amounts of vitamin A.
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Protects vitamin A from oxidation both in the intestines and in tissues. Therefore, if there is a lack of vitamin E, the body cannot absorb the required amount of vitamin A, and therefore these two vitamins must be taken together.
Deficiency can lead to impaired conversion of vitamin A to its active form. Because the body, in the absence of adequate zinc, cannot synthesize vitamin A-binding protein, the carrier molecule that transports vitamin A across the intestinal wall and releases it into the blood, zinc deficiency can lead to poor tissue uptake of vitamin A.
These two components are interdependent: for example, vitamin A promotes the absorption of zinc, and zinc also acts on vitamin A.
Mineral oil, which can sometimes be taken as a laxative, can dissolve fat-soluble substances (such as vitamin A and beta-carotene). These vitamins then pass through the intestines without being absorbed as they are dissolved in mineral oil from which the body cannot extract them. Continuous use of mineral oil, therefore, can lead to vitamin A deficiency.
You can not take vitamin A together with retinoids - its structural, and, as a rule, synthetic analogues, since this combination can be harmful.
For the normal absorption of vitamin A, the presence of fats and proteins in the diet is necessary. The difference between edible and mineral oil is that the body can absorb edible fat along with the vitamin A dissolved in it. Mineral oil is not absorbed by the body.
The modern pharmaceutical industry offers a large number of vitamin complexes, but only in some of them the ratio of vitamins is balanced in a way that is best for their absorption. In most cases, in multivitamin preparations, vitamins are selected “for quantity”, and can even weaken the effect of each other. Therefore, if you need vitamin A, it is better to eat foods with its natural content.