Vitamins

Vitamins

Vitamins are essential nutrients that the body cannot or only insufficiently produce itself. Therefore, vitamins or their precursors (provitamins) must be supplied with food.

What are vitamins anyway?

Vitamins have numerous biocatalytic functions in the organism, which means that they ensure that metabolic processes can take place undisturbed. It is important to know that the metabolism and thus the effect of individual vitamins depends on other vitamins.

In principle, you can cover your vitamin requirements with a wholesome diet . Optimal nutrition, however, is not easy: On the one hand, many people lack the time to freshly prepare food, and on the other hand, many foods lose significant amounts of vitamins due to changed cultivation conditions and long transport routes. Potatoes, for example, have up to 25 percent less vitamin C than they did 20 years ago.

An insufficient supply of vitamins can lead to a variety of deficiency symptoms and diseases. Such a deficiency can be favored by various factors – for example smoking , alcohol, an unbalanced diet , chronic illnesses, taking medication or diseases of the digestive system . Competitive athletes, growing children and young people, pregnant women or nursing mothers also have an increased need for vitamins.

Which groups of vitamins are known?

The vitamins can be differentiated according to their solubility in water or fat. The water-soluble vitamins include:

  • Vitamin B1
  • Vitamin B2 (riboflavin)
  • Vitamin B3 (niacin)
  • Vitamin B5 (pantothenic acid)
  • Vitamin B6 (pyridoxine)
  • Vitamin B9 (folic acid)
  • Vitamin B12 (cobalamin)
  • Vitamin H (biotin)
  • vitamin C

Water-soluble vitamins cannot be stored in the body, or can only be stored briefly (with the exception of vitamin B12).The fat-soluble vitamins include:

  • Vitamin A
  • Vitamin D
  • Vitamin E.
  • Vitamin K

Fat-soluble vitamins can only be absorbed together with fat. That is why you should always use a little fat when preparing carrots ( vitamin A ) or broccoli ( vitamin K ), for example. In contrast to the water-soluble vitamins, fat-soluble vitamins can be stored in the body.

Vitamin A (retinol) – part of a healthy diet

Vitamin A is necessary for numerous body functions: the visual function, the cell division of the skin and mucous membrane, the embryonic development, the body and cell growth and the ability to reproduce.

Vitamin A is one of the antioxidants and is important for the cardiovascular system . The fat-soluble vitamin A is contained in animal foods. Plant foods contain provitamin A, for example β-carotene, which can be converted into vitamin A in the body as needed.

An under supply of vitamin A can manifest itself in visual disturbances (night blindness), cornification disorders of the skin and mucous membranes, growth and development disorders in children and unborn babies, fertility disorders and an increased risk of cancer . Vitamin A and its derivatives are used therapeutically for some skin diseases such as acneand psoriasis used.

This is how much vitamin A the body needs

The recommended daily intake for adults is 0.8 to 1.0 milligram equivalent. Because vitamin A is fat-soluble, the body can store it, so be careful with high doses of vitamin A. Pregnant women and women who want to have children should not consume more than 1.1 milligram equivalent of vitamin A daily. Too much vitamin A during pregnancy can cause serious damage to the unborn child.

There is a lot of vitamin A in liver, spinach, carrots, milk and dairy products.

Vitamin B1 (thiamine) – important for carbohydrate metabolism

Thiamine has a central function in the metabolism of carbohydrates and is therefore particularly required in tissues with a high turnover of carbohydrates – for example in nerve cells.

Thiamine is found mainly in the germs and surface layers of grains and rice, but also in nuts and pork.

Thiamine deficiency known as “Beri-Beri”

The symptoms of a thiamine deficiency were already known in the 17th century under the name “Beri-Beri”. This disease is characterized by severe cardiovascular disorders – thousands of people died in East Asia and Japan at the time. Such a severe vitamin deficiency is practically non- existent these days. A slight deficiency manifests itself in the form of tiredness, loss of appetite, tremors, muscle weakness and increased irritability.

The thiamine requirement depends on age and performance. For adults, a daily intake of 1.0 to 1.3 milligrams is recommended ( DA-CH reference value ).

For various diseases – for example diabetes mellitus, alcoholic polyneuropathy or other disorders of the nervous system – there is an increased need for vitamin B1.

Vitamin B2 (riboflavin) – important for energy production

Riboflavin is important for the metabolism of carbohydrates , fatty acids and purines ( proteins ) as well as for energy production. Riboflavin has an antioxidant effect and is important for detoxification processes and the immune system.

A deficiency in riboflavin usually occurs together with a deficiency in other B vitamins and manifests itself in the form of inflammatory changes in the mucous membrane (e.g. angular mouth ulcers ), conjunctivitis and corneal inflammation of the eye , cornification disorders of the skin, anemia , listlessness or depressive mood .

The riboflavin requirement depends on the energy expenditure and is 1.0 to 1.4 milligrams daily in adults

Vitamin B3 (nicotinic acid) for fat metabolism and detoxification

Nicotinic acid or niacin (formerly also called vitamin B3) is involved in carbohydrate , protein and fat metabolism , in energy production and in detoxification and antioxidant systems .

Wheat bran, yeast, veal and pork liver, roasted peanuts, chicken and beef are rich in this vitamin.

Nicotinic acid deficiency is known as “pellagra”

In the 18th century, the connection between nicotinic acid deficiency and a one-sided corn diet was known for the first time in Spain under the disease “Pellagra”. This disease was associated with “rough skin” (pellagra), headaches , digestive disorders and central nervous disorders. Slight deficiency symptoms are shown by skin and mucous membrane disorders (burning tongue, inflammation of the corners of the mouth, reddened, flaky skin) or digestive disorders .

Use in lipid metabolism and cardiovascular diseases

Nicotinic acid is used therapeutically for lipid metabolism disorders and cardiovascular diseases , as it lowers cholesterol and triglyceride levels and increases HDL cholesterol in a dose-dependent manner. Its vasodilator effect is used in cases of high blood pressure or migraines .

As a side effect, digestive disorders and a so-called flush can occur (reddening of the skin, tingling, drop in blood pressure). For this reason, treatment with higher doses must be started slowly “creeping in” and under medical supervision.

The recommended daily dose is 11 to 14 milligram equivalents for adults.

Vitamin B5 (pantothenic acid) for the formation of substances

As a component of a coenzyme, vitamin B5 is involved in the metabolism of carbohydrates , fats and proteins ; it is also required for the formation of various endogenous substances.

Substances that require vitamin B5 to form include cortisol, cholesterol , vitamin D and hemoglobin .

A deficiency usually occurs in combination with a deficiency in other B vitamins and manifests itself in relatively unspecific complaints such as tiredness, headache and muscle pain , gastrointestinal disorders or reduced immune defense .

The recommended daily intake for adults is six milligrams.

Vitamin B6 (pyridoxine) – vitamin for metabolism

As a coenzyme, vitamin B6 is involved in numerous metabolic processes. It also plays a role in the formation of hemoglobin and in stabilizing the immune system.

Foods that contain vitamin B6 are: meat, fish, vegetables, fruits, dairy and whole grain products.

A deficiency usually occurs in connection with a deficiency in other B vitamins and can manifest itself in the form of depression , muscle weakness, neurological disorders, anemia ( anemia ) or changes in the skin and mucous membranes.
Vitamin B6 in PMS
Among other things, vitamin B6 can lead to a reduction in symptoms in premenstrual syndrome (PMS) . It is also used to prevent diabetic neuropathy . Together with vitamin B12 and folic acid , it is used to lower high homocysteine ​​levels, a risk factor for cardiovascular diseases . Studies that show a clear effectiveness are still pending.

The recommended daily intake for adults is 1.2 to 1.6 milligrams.

Vitamin B9 (folic acid) – vitamin for cell divisio


Folic acid is involved in numerous metabolic processes – especially tissues with a high rate of cell division (e.g. bone marrow, skin , mucous membranes) are therefore dependent on folic acid. Folic acid is also involved in the conversion of the vascular damaging homocysteine ​​into methionine.

Meat, vegetables (lettuce, spinach), egg yolks, grains and legumes are rich in folic acid. However, a large part of the folic acid content is lost through food processing and storage.

A deficiency in folic acid manifests itself through paleness, tiredness, changes in the mucous membrane, gastrointestinal disorders , growth disorders and an increased risk of arteriosclerosis (“vascular calcification”).

Because of the generally poor supply of folic acid, it is added to some foods with good success in some countries, such as the USA or Hungary. This is not yet the case in Germany, although young women in particular have low folic acid levels.

Folic Acid During Pregnancy

Folic acid is particularly important for pregnant women , because folic acid deficiency can lead to disorders in the development of the child’s brain and spinal cord. Possible consequences are neural tube defects (for example spina bifida, “open back”). Therefore, women are recommended to take folic acid as early as possible when planning pregnancy (400 microgram equivalent / day).

Folic acid can prevent cardiovascular diseases

Folic acid can lower the homocysteine ​​level in the blood and thus prevent cardiovascular diseases . It is particularly recommended to take vitamins B6 and B12 together . An additional supply of folic acid can also be useful for chronic inflammatory bowel diseases , diabetes mellitus , or tumor diseases .

A daily intake of 300 micro grams equivalent is recommended for adults.

Vitamin B12 (cobalamin) – vitamin for metabolism

Just like folic acid, vitamin B12 is involved in numerous metabolic processes in the body. It also plays a role in all cell division processes. Vitamin B12 and folic acid often complement each other in their effects.


Although humans can produce vitamin B12 in the intestines, they are dependent on additional intake from food. Vitamin B12 is mainly found in animal foods – for example in meat, fish and eggs. In order to be able to absorb vitamin B12 in the small intestine , a protein from the gastric mucosa ( intrinsic factor ) is necessary.

A deficiency in vitamin B12 can manifest itself through tiredness and general weakness, nerve disorders, impaired blood formation (megaloblastic anemia ) or gastrointestinal disorders .

The recommended daily intake for adults is three micro grams. An additional gift can be given in particular Diabetes mellitus or cardiovascular diseases can be useful.

Vitamin C – the most important antioxidant

Vitamin C is involved in numerous metabolic processes in the body – for example in various detoxification processes, iron absorption and in protection against free radicals and cancer-causing substances.

Vitamin C is the most important antioxidant for the human and animal organism. In the course of evolution, humans and monkeys have lost the ability to produce vitamin C themselves and are therefore dependent on food intake. Rose hips, peppers, black currants, sea buckthorn, broccoli and citrus fruits are particularly rich in vitamin C.

Vitamin C deficiency can have many consequences

Because vitamin C is also significantly involved in collagen synthesis , a deficiency becomes noticeable in the form of skin and vascular damage: mucosal bleeding, bleeding gums and tooth loss , bleeding in the muscles and wound healing disorders . But weakness and tiredness as well as depression , cardiovascular diseases or a weakened immune system can be the result of a vitamin C deficiency. The typical vitamin C deficiency was known to seafarers as the deadly disease “scurvy” and the result of a one-sided diet without fresh fruit and vegetables.

When an additional vitamin C supply makes sense

The recommended daily intake for adults is 100 milligrams. An additional supply can be particularly useful in the case of diabetes mellitus , a tendency to infection, allergies and cardiovascular diseases .

Vitamin D – for bones and skin

The human body can produce vitamin D itself – in the skin under the action of UV light. However, this amount is not enough to meet demand.

Vitamin D promotes skeletal growth and bone strength. But it is also important for the formation of teeth , the structure of the skin , the muscles and the immune system. Sea fish, butter, cream, cheese, chicken eggs and mushrooms are rich in vitamin D.

Extra vitamin D for infants

The classic vitamin D deficiency manifests itself as rickets in children and as osteomalacia in adults. Both diseases lead to severe bone deformities. In order to prevent rickets, it is now recommended that infants receive 10 micrograms (400 IU) of vitamin D daily at least until the end of their first year of life. There is evidence that this can also lower the risk of type I diabetes .

Vitamin D is also used therapeutically in cases of parathyroid hormone deficiency, osteoporosis , psoriasis , rickets and when taking anti-epileptic drugs . In the case of chronic renal insufficiency, intake in the active form (calcitriol) is necessary.

Be careful with very high doses

A daily intake of 20 micro grams (= 800 IU) is recommend for adults. Since vitamin D can be store in the body, one should be careful with very high doses. Interactions with other drugs and contraindications must be consider.

Vitamins E (tocopherol) – part of the cell membrane

Vitamins E (tocopherol) is the most important antioxidant vitamin and works together with other radical scavengers such as vitamin C , selenium and coenzyme Q10. Vitamin E is contain in all cell membranes and protects these and other structures from oxidation.

Vitamin E also regulates blood clotting and clot formation, activates the immune system and inhibits inflammatory processes.

Vitamins E in vegetable oils

Vitamin E is found primarily in vegetable oils such as wheat germ, corn and sunflower oils, but also in nuts, egg yolks and sea fish. The used vitamin E is regenerated by vitamin C.

Consequences of a vitamin E deficiency

The consequences of a vitamin E deficiency are neurological disorders, susceptibility to infections, fertility disorders and an increased risk of cardiovascular diseases and cancer .

Prophylactic benefit not clearly proven

Vitamin E can be use, for example, for the prophylaxis and treatment of cardiovascular or rheumatic diseases , diabetes mellitus and cancer .

However, the prophylactic benefit of vitamin E has not been clearly proven. Some studies have shown that very high doses of vitamin E have no beneficial, but rather the opposite effect. One reason for this may be that often only one substance from the group of E vitamins – alpha tocopherol – was examine. However, there are eight different E vitamins in natural products. But if the alpha tocopherol is take alone in high doses, it can even hinder the other E vitamins in their effect. Therefore, you should always make sure that you use natural vitamin E, which contains all eight substances, and not just synthetically produced alpha-tocopherol.

Vitamins H (biotin) for skin, hair and nails

As a coenzyme, biotin is involved in numerous metabolic processes. In particular, it plays an important role in DNA formation – and thus all cell division processes. Therefore, it is especially important for the health of the skin, hair and nails .

Foods rich in biotin include brewer’s yeast, liver, milk and milk products, eggs, spinach, asparagus and soybeans.

Signs of a biotin deficiency

With a biotin deficiency, skin changes , hair loss , gastrointestinal disorders , growth and development disorders in children as well as neurological disorders can occur.

A biotin supply can be useful for diabetes mellitus , hair loss and brittle fingernails. A daily intake of 30 to 60 micro grams is recommend for adults.

Vitamins K (phylloquinones) for blood clotting

The fat-soluble vitamin K plays an important role in blood clotting . Without his influence, wounds would continue to bleed. Vitamin K is also important for bone strength. The vitamin also has antioxidant properties .

VitaminK is mainly found in green vegetables such as broccoli, Swiss chard, kale, Brussels sprouts and spinach, as well as in beef liver, chicken and hen’s eggs

Signs of a vitamin K deficiency can be an increased tendency to bleed in organs and mucous membranes and a decreased bone density.

Extra vitamin K for newborns

Because the liver of newborns is not yet fully developed, they are given additional vitamin K after birth. Even with existing or threatened osteoporosis , an adequate vitamin K supply should be ensured.

For adults, a daily recommended intake of 70 to 80 micro grams applies . You should avoid taking additional vitamin K during therapy with vitamin K antagonists (phenprocoumon, warfarin).

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