Vitamins: Types, functions and recommended requirements at a glance

Vitamins are an integral part of our diet - and at the same time a topic that raises many questions. What vitamins are there, what does your body need them for and how much is useful? This overview provides you with a scientifically sound classification of vitamins, their functions and individual requirements.

What are vitamins?

Vitamins are essential micronutrientsthat the human body needs for a variety of basic functions. In chemical terms, they are organic, low-molecular compounds that are involved in numerous metabolic processes. These include energy production, the normal function of the immune system, blood clotting, cell division and processes associated with protection against oxidative stress .

In contrast to macronutrients such as carbohydrates, fats and proteins, vitamins themselves do not provide energy in the form of calories. Their role is different: They act primarily as cofactors, regulators or protective substances and thus enable biochemical reactions in the body to run smoothly. Without vitamins, many of these processes would not function at all or only to a limited extent.

The human body cannot produce most vitamins itself, or not in sufficient quantities. Therefore, a regular intake through diet is necessary. The scientific literature describes that a long-term deficiency can be associated with functional limitations and typical deficiency symptoms. At the same time: Excessive intake - especially of fat-soluble vitamins such as A, D, E and K - can also be associated with undesirable effects. The decisive factor is therefore not "a lot", but a needs-based and balanced supply.

But not all vitamins are the same. The next overview

Which vitamins are there? - Overview of all vitamins and their functions

Vitamins are diverse - and no two are the same. The following table provides a compact overview of all vitamins, their solubility and the functions they can contribute to in the body.

** The functions mentioned correspond to authorized health claims according to EU Regulation (EC) No. 1924/2006.

Difference between fat-soluble and water-soluble vitamins

Vitamins can be fundamentally divided into fat-soluble and water-soluble vitamins. This distinction describes how vitamins are absorbed, transported and stored in the body.

Fat-soluble vitamins (A, D, E and K) are absorbed together with dietary fats. They can be stored in the body - especially in the liver and fatty tissue. Regular intake is important, but excessive intake should be avoided as these vitamins can accumulate in the body (especially in fatty tissue or selected organs such as the liver).

Water-soluble vitamins (vitamin C and the B vitamins) dissolve in water and are only stored to a limited extent. Excess amounts are usually excreted via the metabolism. This is particularly noticeable with vitamin B2 (riboflavin), which in large quantities leads to bright yellow urine. A continuous supply via the diet is therefore particularly relevant.

This distinction helps to better classify the role of individual vitamins and to understand their supply in everyday life.

Which vitamins does the body need?

So we now know how important vitamins are. But how many vitamins does the body actually need? Individual requirements can vary and depend on factors such as age, gender, diet, lifestyle and particular phases of life. For guidance, the German Nutrition Society (DGE) publishes scientifically based reference values for the daily vitamin intake of healthy adults. The following table shows the recommended daily intake for adults. In many situations, however, the recommended daily amount is not sufficient and there is an increased requirement.

Vitamins and dietary supplements - a classification

Vitamins are among the nutrients that are talked about a lot in everyday life - and about which many questions remain unanswered at the same time.

Vitamins are generally absorbed through the diet and are an integral part of a balanced nutrient supply. Many foods provide relevant amounts of individual vitamins - fresh fruit and vegetables such as citrus fruits or peppers, for example, are well-known sources of vitamin C.

In everyday life, however, it is clear that this supply is not always sufficient. An insufficient supply of certain vitamins is described in certain population groups. Vitamin D is a frequently cited example: In Central Europe, the body's own production is limited in the winter months (from October to April) due to low sun exposure, which is why a low vitamin D status is often observed during this time.

Individual requirements also play a role. In special life situations - such as during growth, pregnancy or when food intake is restricted - the need for individual vitamins may be increased. In such cases, a supplementary intake of individual vitamins is considered in the scientific discussion.

It is not possible to say in general terms whether dietary supplements are useful. The decisive factor is your individual requirement - and this is best classified on the basis of data. You can determine your vitamin D status, for example, via a medical blood test or a vitamin D test (laboratory test for home use). On this basis, needs-based supplementation is possible, always as a supplement and not as a substitute for a balanced diet.

Vitamin supplements are available in different dosage forms. Which form is appropriate in each individual case depends, among other things, on the properties of the vitamin in question - such as its solubility, stability and the way it is absorbed in the body.

Fat-soluble vitamins such as vitamin D are often offered in oil-based form, for example as vitamin D3K2 drops or as capsules with MCT oil. Vitamin D is sometimes found in combination with vitamin K, as both are fat-soluble and can be processed together in corresponding preparations. Vitamin K is also important for calcium homeostasis in the body - especially with increased vitamin D intake.

Water-soluble vitamins, especially the B vitamins, are often offered as combination preparations such as a vitamin B complex . Other vitamins, such as vitamin C, are available in various dosage forms, including vitamin C capsules, tablets, effervescent tablets or powder.

Which dosage form is chosen is primarily a question of individual preference, tolerance and use in everyday life

Conclusion - understanding vitamins instead of blanket supplementation

Vitamins are essential micronutrients with a variety of functions in the body. Which vitamins are required and in what quantity depends on individual needs. Factors such as diet, lifestyle and particular phases of life play a key role in this. Reference values such as those of the DGE offer helpful orientation, but are no substitute for personal classification. Food supplements can also only be meaningfully evaluated in the context of your own needs. The decisive factor is therefore not to take as many vitamins as possible, but to consciously understand vitamins and integrate them into your own health strategy in line with your needs - informed, data-based and individually.