Vitamins - what do we need and why?
At the beginning, a little terminology and general information - then specific to each vitamin separately.
What are vitamins?
Vitamins are organic chemical compounds that are necessary for the normal functioning of the body. Vitamins are necessary for the normal functioning of all organs and systems - the growth and development of the body, visual and hematopoietic processes, bone calcification and other vital functions. Vitamins increase the body's ability to fight infections and adapt to a variety of adverse conditions. Vitamins do not work in isolation, they are closely related to enzymes and hormones and play an important role in virtually all metabolic processes.
Vitamins need to be taken in with food, because the body is either unable to synthesize them or is unable to synthesize enough, such as vitamin K. Some B vitamins are also synthesized by bacteria in the gut. Antibiotics and sulfanylamides inhibits the synthesis of vitamins in the gut (kills the bacteria that synthesize them) and, if used for a long time, can cause hypovitaminosis - therefore, to restore the balance of bacteria during and after the use of antibiotics, it is recommended to take probiotics.
The term vitamins does not include three other groups of essential nutrients: minerals, essential fatty acids, and essential amino acids.
Vitamins fall into two categories:
- Fat-soluble vitamins - A, D, E and K. They are stored in the liver and adipose tissue and the reserves of these vitamins in the body can remain for days and sometimes months. It is important to be ingested with food enough fat, which helps the body absorb fat - soluble vitamins through the intestinal tract. If you do not have enough fat, you can become deficient in these vitamins with all the health problems that come with it.
- Water-soluble vitamins - do not accumulate in the body. The nine water-soluble vitamins are vitamin C and all B vitamins. Any residue or excess is excreted in the urine. For this reason, to prevent a deficiency of these vitamins in the body - they must be taken regularly. The exception is vitamin B12, which can be stored in the liver for many years.
Units of measurement for vitamins
3 types of units are used to measure the amount of vitamins:
- Milligrams - 1 thousandth of a gram and is usually expressed as mg.
- Micrograms: 1 ppm and are usually expressed in μg or mcg. 1000 micrograms is equal to 1 milligram.
- International units of measurement, sometimes used to measure the amount of vitamins A, D and E, and are usually given in IU (International Units). The conversion of milligrams (mg) and micrograms (μg) to IU depends on the type of vitamin.
Vitamin imbalance in the body
- Avitaminosis - complete lack of one or more vitamins.
- Hypovitaminosis - what vitamin is inadequate.
- Hypervitaminosis - Vitamins are ingested disproportionately. Any vitamin, if used for a long time in high doses, can cause abnormalities. If you eat only fresh foods, this condition is unlikely to ever happen, but you should be careful if you take any additional vitamins or complexes. The most common are hypervitaminosis A and D. Hypervitaminosis usually occurs in infants and young children. In adults, possible hypervitaminosis may result in mucosal rupture, headache, nervousness, and hepatic impairment.
Excessive use of vitamin D increases the accumulation of calcium salts in the body, loss of appetite, constipation, vomiting, weight loss, high blood pressure, growth retardation in children, possible kidney disease.
Who needs to take extra vitamins?
- For people with dietary restrictions, such as following a restrictive diet (such as Dican diet).
- For people with certain chronic diseases.
- For women during pregnancy and lactation.
- If a vitamin deficiency is detected.
- In the autumn and winter season, it is recommended to use a vitamin complex to strengthen immunity. It is advisable to consult your doctor before use.
The role of vitamins in the body
Some sources list fourteen vitamins, including choline, but in most cases thirteen vitamins are distinguished.
Also known as retinol. Needed for eye health and the proper functioning of the body's immune system. Helps build and maintain healthy teeth, bones, soft tissues, mucous membranes and skin. Promotes hair growth, helps against allergies.
Good sources of vitamin A (retinol)
Cheese, eggs, fatty fish, dairy products and especially liver, which is especially rich in vitamin A, such as liver pate. Pregnant women should avoid frequent consumption of liver or liver products, as too much vitamin A can harm the baby.
You can also get vitamin A by including foods that contain beta carotene, as the body can convert it into retinol. The main sources of beta carotene are:
- Yellow, red and green (leafy) vegetables such as spinach, carrots, sweet potatoes, red pepper.
- Yellow fruits such as mango, papaya and apricots.
How much vitamin A should be taken?
The recommended amount of vitamin A for adults aged 19 to 64 is:
- For men 700 - 900 dienāg per day.
- For women 600 - 700 dienāg per day.
Remember that unused vitamin A is stored in your body for future use, which means that you do not have to take it every day.
What happens if you take too little vitamin A?
Vitamin A deficiency causes vision problems - the eye's ability to adapt to light and darkness is reduced. Growth disturbances or weight loss may occur, changes in the mucous membranes, reduced resistance of the body to infectious diseases.
What happens if you take too much vitamin A?
Some studies suggest that long-term intake of more than 1.5 mg (1,500 g) of vitamin A daily may increase the risk of bone fractures, especially in the elderly, who are already at increased risk of osteoporosis. Increased attention to vitamin A intake should be considered in patients with hepatic impairment due to the potential for hepatic impairment. Cracks in the corners of the mouth may appear in adults.
Vitamin A is found in many vitamin complexes (multivitamins) and supplements (for example, fish liver oil is high in vitamin A). If you are taking vitamin supplements that contain vitamin A, make sure that your average daily intake of food with food supplements does not exceed 1.5 mg (1500 µg).
B vitamins and folic acid
The group of B vitamins includes - vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), B12 vitamin (cobalamin).
It is part of enzymes (helps to break down food and turn it into energy) and participates in metabolic processes. Needed in the synthesis of acetylcholine, which plays an important role in the transmission of nerve impulses.
Good sources of vitamin B1 (thiamine)
Peas, some fresh fruit (such as bananas and oranges), nuts, wholemeal bread, seeds, bran, oatmeal, liver, pork, egg yolk.
How much vitamin B1 should be taken?
The recommended amount of vitamin B1 for adults aged 19 to 64 years is:
- For men 1 - 1.4 mg per day.
- For women 0.8 - 1.2 mg per day.
Thiamine cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin B1?
Alcoholics are evolving Beriberi disease and Vernike encephalopathy. Vitamin B1 deficiency is observed in patients with anorexia, renal patients on dialysis, HIV-infected, gastrointestinal malabsorption, heart patients who use diuretics.
What happens if you take too much vitamin B1?
Excessive intake of B1 with food supplements may cause stomach upset, headache, sweating, tachycardia, itchy skin.
Works with other B vitamins. It is necessary for the growth of the body, respiratory processes, the production of red blood cells and the functions of the central nervous system. Helps release energy from protein.
Good sources of vitamin B2 (riboflavin)
Dairy products, yeast, eggs, mushrooms, asparagus, cabbage, cauliflower, potatoes, oranges, sunflower seeds, brown rice, whole grain products, green leafy vegetables, pork, liver, fish.
UV light can destroy riboflavin, so these foods must be protected from direct sunlight.
How much vitamin B2 should be taken?
The recommended amount of vitamin B2 for adults aged 19 to 64 years is:
- For men 1.3 - 1.5 mg per day.
- For women 1.1 - 1.5 mg per day.
Riboflavin cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin B2?
Deficiency causes the corners of the mouth to rupture. If vitamin B2 is lacking during pregnancy, fetal malformations may occur.
What happens if you take too much vitamin B2?
Excessive intake of dietary supplements can cause fatty liver degeneration.
Vitamin B3 (also called vitamin PP)
Niacin helps the digestive system to function, is necessary for skin health and the normal functioning of the nervous system.
Good sources of vitamin B3 (niacin, nicotinic acid)
Whole grain products, peas, beans, mushrooms, meat (especially pig liver), kidneys, mackerel.
How much vitamin B3 should be taken?
The recommended amount of vitamin B3 for adults aged 19 to 64 is:
- For men 16.5 - 20 mg per day.
- For women 13.2 - 16 mg per day.
In high doses (around 500 mg), nicotinic acid is used as a medicine to lower cholesterol and dilate blood vessels.
Niacin cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin B3 / PP?
When nicotinic acid is deficient in the body, oxidation processes are disrupted and PP avitaminosis develops - pelagra. Inflammation of the skin (dermatitis) is a characteristic feature of pelagra. Gastrointestinal disorders also develop, in severe cases - nervous system disorders, up to dementia. Today, a pelagic-like disorder occurs in Europe - a pelagroid, characterized only by skin changes. Fatigue, muscle weakness, loss of appetite, poor sleep, inability to concentrate, depression, hypersensitivity may also occur.
What happens if you take too much vitamin B3 / PP?
Overdose of nicotinic acid preparations causes redness and burning of the skin, which resolves quickly. Prolonged overdose may lead to hepatic impairment, elevated bilirubin amount in the blood
It is required for the synthesis of coenzyme Q as well as for the synthesis and metabolism of proteins, carbohydrates and fats. Performs very comprehensive functions in the body, participates in biological processes, regulates blood cholesterol levels, participates in the hematopoietic process, promotes the absorption of iron.
Good sources of vitamin B5 (pantothenic acid)
Pantothenic acid is found in varying amounts in almost all vegetables and whole grains. Good sources of B5 are rosehips, blackcurrants, sweet peppers, dill, parsley, avocados, mushrooms, eggs, meat (especially liver and kidneys).
How much vitamin B5 should be taken?
The recommended amount of vitamin B5 for adults aged 19 to 64 years is 5 to 6 mg per day, for pregnant women about 6 mg per day, and for breastfeeding about 7 mg per day.
Pantothenic acid cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin B5?
Pantothenic acid deficiency is usually associated with deficiency of other nutrients, making it difficult to identify the specific features of pantothenic acid deficiency. Only general signs of vitamin deficiency are mentioned - fatigue, reduced immunity, anemia, delayed wound healing, decreased libido, delayed fetal development during pregnancy, growth retardation in children.
What happens if you take too much vitamin B5?
There are no data on the toxicity of pantothenic acid in humans at high doses. Some individuals taking high doses of pantothenic acid as an additive (eg 10 g / day) develop mild diarrhea and gastrointestinal disorders, but the mechanism of this effect is unknown.
It is part of enzymes, participates in the metabolism of amino acids and fats, is necessary for the normal functioning of the brain.
Good sources of vitamin B6 (pyridoxine)
Legumes, potatoes whole grains, eggs, cheese, herring, pork, liver.
How much vitamin B6 should be taken?
The recommended amount of vitamin B6 for adults aged 19 to 64 in various sources ranges from 1.0 to 2.0 mg per day, on average:
- For men 1.5 mg per day.
- For women 1.3 mg per day.
Pyridoxine cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin B6?
Classical clinical symptoms include rash and inflammation around the mouth and eyes, as well as neurological effects including somnolence and peripheral neuropathyaffecting the sensory and motor nerves in the hands and feet. Nervousness, convulsions, anemia and reduced immunity are also common.
Vitamin deficiency can occur with the use of anti-tuberculosis drugs.
What happens if you take too much vitamin B6?
Excessive intake of food supplements can cause liver damage and sensory neuropathy.
Vitamin B7 (Biotin, vitamin H, coenzyme R)
Biotin plays a key role in the metabolism of lipids, proteins and carbohydrates - it is involved in the synthesis of fatty acid hormones and cholesterol.
Good sources of vitamin B7 (biotin)
Various legumes, lentils, green peas, sunflower seeds, carrots, cauliflowers, mushrooms, cereals, dairy products, eggs (especially egg yolk), meat (especially liver and kidney), seafood
How Much Vitamin B7 Should You Take?
There is no specific recommended daily dose for biotin due to insufficient evidence / studies to determine this. In various sources, its maximum tolerable intake level (UL) ranges from 25 to 100 mg per day.
Adults over the age of 19 are recommended to take about 0.15 mg per day.
Bacteria that live naturally in your gut are able to produce biotin, so it is not clear if everyone needs extra biotin from their diet - it depends to a large extent on the action of these bacteria in your body.
What happens if you take too little vitamin B7?
Biotin deficiency in adults does not usually cause significant health problems. Symptoms are usually cosmetic problems that are related to the health of the hair, nails and skin. Loss of appetite, nausea, fatigue, muscle pain are also possible. However, biotin deficiency can cause growth and neurological disorders in infants.
What happens if you take too much vitamin B7?
No health problems have been observed with too much biotin.
Acts as a coenzyme involved in the metabolism of nucleic acids and amino acids. This is necessary for the normal cell division process, especially during pregnancy and infancy, when enough growth is needed to provide enough vitamin B9. Along with vitamin B12 promotes erythropoiesis - the formation of red blood cells.
Today, many foods are fortified with folate in the form of folic acid.
Good sources of vitamin B9 (folic acid or folate)
Parsley leaves, spinach, lettuce, lettuce, beets, cabbage, sunflower seeds, avocados, legumes, liver, eggs.
How much vitamin B9 should be taken?
The recommended amount of vitamin B9 for adults aged 19 to 64 years is:
- For men 400 µg per day.
- 300 dienāg per day for women, 600 µg per day during pregnancy, 500 µg per day during breastfeeding.
Vitamin B9 cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin B9?
Deficiency causes anemia, homocysteine (vascular damage, blood clots, stroke, risk of heart attack). Ingestion of too little B9 during pregnancy may cause fetal malformations - spina bifida, sphincter of the spine, werewolf, hare.
What happens if you take too much vitamin B9?
Excessive intake of food supplements can cause gastrointestinal disorders, insomnia, mental disorders, allergies.
Involved in the metabolism of carbohydrates, proteins and lipids (fats). It plays an important role in the formation of blood cells in the bone marrow.
Good sources of vitamin B12 (cobalamin)
Fish, crustaceans, meat, eggs, dairy products. It is also found in small quantities in fermented plant products, such as sauerkraut.
How Much Vitamin B12 Should You Take?
The recommended amount of vitamin B12 for adults aged 19 to 64 is 1.5 - 2 µg per day.
If you have meat, fish and dairy on your menu, you are more likely to get enough vitamin B12 from your diet.
Vitamin B12 is recommended for vegans and vegetarians who do not eat fish, as it is not found naturally in foods such as fruits, vegetables and grains.
What happens if you take too little vitamin B12?
Vitamin B12 deficiency causes anemia, elevated methylmalonic acid and homocysteine level peripheral neuropathy, sensory loss, memory loss and other cognitive impairment. It can also cause symptoms of mania and psychosis. If left untreated, it can cause permanent damage to the brain and nervous system, and in extreme cases, paralysis.
The risk of B12 deficiency is higher in the elderly as its intestinal absorption decreases with age.
What happens if you take too much vitamin B12?
No health problems have been reported with too much cobalamin.
Also called ascorbic acid, L-ascorbic acid or L-ascorbate. Promotes collagen production, wound healing and bone formation. Promotes vision improvement and dental, gum, skin health. Improves wound healing. Lowers blood cholesterol. Strengthens blood vessels, supports the immune system, helps the body absorb iron and acts as an antioxidant.
Good sources of vitamin C (ascorbic acid)
Red and green peppers, oranges, grapefruit, kiwi, strawberries, spinach and other greens, leafy vegetables, tomatoes, potatoes, green peas, cabbage (including pickled), paprika, greens - onions, spinach, dill, celery and parsley pages.
It must be remembered that all these products must be eaten fresh, because during cooking (heating) vitamin C is destroyed.
How Much Vitamin C Should You Take?
The recommended amount of vitamin C for adults aged 19 to 64 is:
- For men 90 mg per day.
- For women, 75 mg per day. during pregnancy - 85 mg per day, while breastfeeding - 120 mg per day.
People who smoke usually have lower levels of vitamin C than non-smokers. This may be due to an elevation oxidative stress therefore, smokers are advised to take an extra 35 mg of vitamin C every day.
Ascorbic acid cannot accumulate in the body, so it must be taken with food every day.
What happens if you take too little vitamin C?
Complete lack of vitamin C in the body causes scurvy or cinguwhich, if left untreated, ends in death.
Partial vitamin C deficiency is quite common and includes drowsiness, persistent headaches, depressed mood, tiredness, bleeding gums, frequent colds and infectious diseases.
What happens if you take too much vitamin C?
The maximum dose of vitamin C for adults is 2000 mg per day.
It is difficult to get too much vitamin C from your diet, but you should pay close attention to your intake if you are taking supplements.
Too much vitamin C intake is unlikely to cause significant health problems, but if a person takes more than 1000 mg of vitamin C per day, the body will not be able to absorb it. It can cause diarrhea and discomfort in the gastrointestinal tract. Prolonged intake of too much vitamin C may lead to the formation of kidney stones and increase the risk of cardiovascular problems in postmenopausal women, but there is insufficient evidence to support this.
People with congenital haemochromatosis (iron malabsorption) should consult their doctor before taking vitamin C supplements. High levels of vitamin C can cause tissue damage.
It is also known as the "sun vitamin" because the body produces it under the influence of sunlight. Helps regulate the amount of calcium and phosphate in the body is therefore important for bone and dental health, prevention of osteoporosis, prevention of conjunctivitis (inflammation of the lining of the eye). Supports the health of the immune system, brain and nervous system, regulates insulin levels.
There are some reports that vitamin D reduces the risk of coronavirus (COVID-19). However, there is currently insufficient evidence to recommend the use of vitamin D for the prevention or treatment of COVID-19.
Good sources of vitamin D.
Mostly Sun. Exposure to UVB rays from the sun or other sources causes the body to produce vitamin D. This vitamin is also found in fatty fish (salmon, sardines, mackerel), egg yolks, beef liver and mushrooms.
Getting enough vitamin D from food alone is very difficult. Therefore, in winter, it is recommended to take vitamin D with fortified or vitamin D-fortified foods in which it is available in two different ways:
- D2 (ergocalciferol).
- D3 (cholecalciferol).
How Much Vitamin D Should You Take?
Being in the sun for 5 to 10 minutes 2-3 times a week allows most people to get enough vitamin D. However, vitamin D breaks down fairly quickly, which means that stocks can run out, especially in winter.
The recommended amount of vitamin D for adults aged 19 to 70 years is 15 µg (600 IU) per day, after the age of 70 20 (g (800 IU) per day for pregnant women and breastfeeding women - 15 µg (600 IU) per day.
Some sources recommend a higher daily dose of 25 µg (800 IU) to 25 (g (1000 IU) per day for people aged 50 years and older.
What happens if you take too little vitamin D?
Low levels of vitamin D can cause a number of problems, especially with bones and muscles, but symptoms may not appear or appear for several years.
Prolonged low levels of vitamin D can cause:
- Osteoporosis - Bones become thin or brittle. The first sign may be a bone fracture due to a minor injury. It often affects the elderly.
- Osteomalacia (rickets in children) - The bones become soft, resulting in bone deformities, short stature, tooth problems, brittle bones and pain when walking.
What happens if you take too much vitamin D?
The maximum dose of vitamin D for adults in most sources is 100 µg (4,000 IU) per day, while there are sources that state that vitamin D toxicity is unlikely if ingested is less than 250 µg (10,000 IU) per day.
Taking too much vitamin D in your gut can absorb too much calcium and increase your blood calcium levels. In turn, high levels of calcium in the blood can cause calcium deposits in soft tissues (such as the heart and lungs), kidney damage and kidney stones, as well as confusion and disorientation, nausea, vomiting, constipation, poor appetite, weakness, loss of appetite and weight loss.
Vitamin E is an antioxidant, also known as tocopherol. It helps the body make red blood cells and use vitamin K. Important for the central nervous system, reproductive system and immunity.
Good sources of vitamin E.
Vegetable oils (for example, wheat germ, rape, almond, sunflower, safflower, maize and soybean oils), nuts (for example, almonds, groundnuts and hazelnuts), seeds (for example, sunflower seeds), green leafy vegetables (for example, spinach and broccoli), avocados, rosehips and sea buckthorn berries, green peas and other legumes.
How Much Vitamin E Should You Take?
Vitamin E is stored in your body before it enters the bloodstream - mainly in the liver, so it does not need to be taken every day.
The highest safe levels of vitamin E for adults are 37.5 µg (1500 IU) per day for natural forms of vitamin E and 27.5 µg (1100 UI) per day for synthetic forms.
The recommended amount of vitamin E for adults aged 19 to 64 years is:
- For men 4 - 10 mg per day.
- For women 3 - 8 mg per day.
What happens if you take too little vitamin E?
Low levels of vitamin E can cause:
- Muscle weakness - Vitamin E is essential for the central nervous system. It is one of the body's main antioxidants, and its deficiency causes oxidative stress, which can lead to muscle weakness.
- Coordination and walking difficulties - Vitamin E deficiency can cause certain neurons called Purkinje neurons to break down, to the detriment of their ability to transmit signals.
- Insensitivity and tingling - damage to nerve fibers can prevent nerves from transmitting signals properly, resulting in these sensations (peripheral neuropathy).
- Visual impairment - Vitamin E deficiency can weaken light receptors in the retina and other cells in the eye. This can cause vision loss over time.
- Immune System Problems - Some studies suggest that vitamin E deficiency can inhibit immune cells. Older people are particularly at risk.
Neuronal sheaths are mostly composed of fat. If your body has too little vitamin E, it contains fewer antioxidants that protect these fats, and the nervous system is disrupted.
What happens if you take too much vitamin E?
High doses of vitamin E supplements (alpha-tocopherol supplements) may increase the risk of cerebral haemorrhage (hemorrhagic stroke) risk. Possible headache, weight loss.
There are studies that suggest that high levels of vitamin E may also increase the risk of birth defects. However, there is no direct evidence for this and further research is needed to clarify this.
K is needed for the blood to clot, helping the wounds to heal. It is important for bone health (needed for calcium absorption).
Good sources of vitamin K.
Vegetable oils - especially soybean and rapeseed oil, turnip leaves, spinach, broccoli, cabbage, kale salad, blueberries, figs, rowanberries, pumpkins, meat, cheese, eggs and soybeans.
How much vitamin K should be taken?
The recommended amount of vitamin K for adults aged 19 to 64 years is:
- For men 65-120 dienāg per day.
- For women 65 - 90 dienāg per day.
Your body stores unused vitamin K in the liver and other tissues in the body, including the brain, heart, pancreas and bone, so you do not need to eat it every day.
What happens if you take too little vitamin K?
Decreased blood clotting, bleeding under the skin and internal organs, decreased bone strength, increased risk of osteoporosis and cardiovascular disease.
Vitamin K deficiency is very rare, except when its absorption from the intestinal tract is impaired. Vitamin K deficiency can also occur after long-term treatment with antibiotics.
What happens if you take too much vitamin K?
Loss of vitamins during cooking
Most vitamins are sensitive to heat and / or water. Water-soluble vitamins, especially most B vitamins and vitamin C, are washed away by boiling the products that contain them in water. Vitamins A, D and E are fat-soluble and leachable in cooking oils. Vitamin C is sensitive to heat, air and water and is therefore usually destroyed during cooking. Other vitamins that can be broken down during cooking are vitamin B6, which is sensitive to heat, air and water, and vitamin E, which is sensitive to heat, air and fat. There are only two vitamins, K and B3, that are stable enough to be well preserved during cooking.
Stable when exposed to air
Stable when exposed to light
Stable under heat
Vitamin B1 (thiamine)
> 100 ° C
Vitamin B2 (riboflavin)
Vitamin B3 (niacin)
Vitamin B5 (pantothenic acid)
Vitamin B6 (pyridoxine)
<160 ° C
Vitamin B7 (biotin)
Vitamin B9 (folic acid or folate)
Vitamin B12 (cobalamin)
Loss of vitamins during cooking
Average losses (%)
Maximum losses (%)
Vitamin B3 (PP)