This article only lists the substances that are essential for humans, other substances are essential for other species. Minerals, trace elements, almost all vitamins , several amino acids and some polyunsaturated fatty acids are essential for humans .
- Arginine (essential for children and old people, otherwise semi-essential)
- Histidine (essential for children)
Semi-essential (also conditionally essential) amino acids can be converted from other essential amino acids, but can become essential amino acids in certain phases of life or due to illnesses.
Two fatty acids are essential for humans: linoleic acid (an omega-6 fatty acid ) and α-linolenic acid (an omega-3 fatty acid ). The body uses these to produce other fatty acids and secondary products ( eicosanoids ) it needs . These include arachidonic acid , eicosapentaenoic acid, and docosahexaenoic acid . Therefore, adding one or more of these secondary products reduces the need for the essential fatty acids. That may be the reason why the characterization “limited synthesizable” can occasionally be found in the literature in this context. However, a diet that has been free of arachidonic acid and eicosapentaenoic acid for years does not automatically lead to deficiency symptoms, while a deficiency in linolenic acid or linoleic acid leads to clear deficiency symptoms.
The metabolic pathways by which the important long-chain fatty acids are produced are influenced by various factors. B. excessive consumption of saturated or monounsaturated fatty acids or alcohol. An excess of omega-6 fatty acids hinders the processing of omega-3 fatty acids , as the enzymes responsible for this (elongase, delta-5 desaturase, delta-6 desaturase) process both substance classes.
The competitive inhibition also works in reverse, but a disproportion between omega-6 and omega-3 fatty acids is practically mostly on the side of omega-6 fatty acids, as these are usually contained in much larger proportions in food.
The essential trace elements are required by the organism in very small quantities and are often important for the action of special enzyme systems (e.g. with transaminases ).
- Cobalt (as a component of vitamin B 12 )
Possibly essential trace elements
A biological function is only assumed for these elements, or the relationships and necessity have not yet been finally clarified.
By definition, all vitamins are essential. The human organism can only produce a limited amount of vitamin D from cholesterol through UV-B radiation , such as sunlight, and niacin (vitamin B3) from the essential amino acid tryptophan. Some vitamins can be absorbed in the form of precursors ( provitamins ), which can be converted into vitamins by the body itself. Others are the organism of symbiotic living organisms (eg. As intestinal bacteria found) are available, such as vitamin K . Vitamin B12, on the other hand, is only synthesized in the large intestine , so at this point it can no longer be absorbed by the small intestine and is therefore excreted again unused; therefore it must be ingested in sufficient quantities with food.
Essential substances in the animal kingdom
For some animals, dietary choline intake is essential. This is especially true for ruminants , as choline is almost completely broken down in the rumen . Choline is not a necessity for humans as long as their diet contains the amino acids methionine and folic acid .
In contrast to the human organism, cats are dependent on an external supply of taurine; Taurine is an essential amino sulfonic acid for your organism.
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