Micronutrient (medicine)

from Wikipedia, the free encyclopedia

In contrast to macronutrients such as fat , carbohydrates and protein , micronutrients are substances that the plant , animal and human organism must absorb without supplying energy . The micronutrients primarily include vitamins , minerals ( bulk elements and trace elements ), proteinogenic amino acids and omega fatty acids . Micronutrients are essential for both catabolic and anabolic reactions in the organism.

Role in metabolism

Micronutrients are involved in the metabolism within the cells and thus in the basic functions of the biological body , such as cell growth and the associated renewal of skin, bones, muscles, blood cells , nerve conduction and the formation of secretions and messenger substances .

Some micronutrients act as cofactors ; H. Low molecular weight substances that contribute to a biochemical reaction (e.g. vitamin K for reactions of γ-glutamyl carboxylase ), others such as niacin form building blocks of various coenzymes ( NAD , NADP ), some derivatives of vitamins serve directly as coenzymes (e.g. Ubiquinon-10 or coenzyme Q10) or are z. B. in fermentation processes such as sourdough - fermentation formed by yeast cells (e.g. acetyl coenzyme A , activated acetic acid from yeast cells). Micronutrients are therefore essential for the function of certain enzymes or exogenous and endogenous enzyme reactions . Others are components for hormones (e.g. iodine as a component of the thyroid hormone ), as electrolytes, or as antioxidants .

Micronutrient supply situation

According to the assessment of the German Nutrition Society , Germany is “not a country with a lack of vitamins” and such diseases are “very rare”. The Federal Institute for Risk Assessment and the German Cancer Research Center also consider the supply to be sufficient in normal cases. Nevertheless, nutritional supplements are often taken out of concern about deficiency symptoms . This is usually superfluous, it can only be useful for certain nutrients and life situations, such as folic acid in early pregnancy or vitamin D in infants and people in need of care.

Insufficient supply

Emergence

Normally, micronutrients are sufficiently supplied to the human body with a balanced diet, as they are found in large quantities in natural foods. Using the example of the ingredients of 100 grams of apple, fresh, unpeeled, it can be seen that in addition to the natural carbohydrates ( types of sugar ) present there as energy suppliers for the above. Metabolism of the same a variety of micronutrients are present in sufficient quantities. An undersupply remains without acute symptoms of malnutrition , if and as long as the body is on depots, e.g. B. in bones , teeth , connective tissue , skin , liver and muscles . By far not all micronutrients can be synthesized by yourself using more complex metabolic steps; if possible, micronutrients are also used up. The vitamins can, for. B. eleven out of 13 organic compounds are in no way synthesized by the organism itself. Both the access to the above Depots of micronutrients and, secondly, the partial ability to synthesize itself, allow the body to compensate for a lack of supply over a certain period of time and to a certain extent .

Does prolonged or chronic illness or other physical stress conditions (e.g. from smoking, environmental toxins → metabolic and oxidative stress ) lead to increased consumption of micronutrients or if one or more of these substances is missing due to insufficient intake in the event of prolonged malnutrition, or if the intake is significant limited, a deficit in micronutrients develops. Then - depending on the extent - there are more or less serious deficiency symptoms. Malnutrition occurs z. B. with too frequent or relatively excessive consumption of "empty energy sources" unknown in nature (colloquially also called "empty calories "). These are industrially manufactured products with a content of macro -nutrients which, although they consume micro-nutrients for their metabolism , have no or only an insufficient content of micro-nutrients (often in the form of carbohydrates or carbohydrate-containing lifestyle products such as cola, soda, potato chips , Bag noodles etc.). Since micronutrients are potentially still being discovered and artificial additives are controversial, especially with regard to their dosage, even products advertised as "with vitamin xy" or similarly advertised products cannot be regarded as equivalent to natural foods. In addition, both deficiency symptoms and overdoses (including hypervitaminoses ) cannot be ruled out through their consumption .

Deficiency symptoms

In particular with long-term and chronic lack of vital substances, u. a. Hypovitaminosis , metabolic disorders occur. For example, scurvy if there is a severe deficiency in vitamin C , etc. a. Bleeding disorders because of numerous protein - synthesis disorders due to vitamin K deficiency (see. Vit K: functions in humans. , Vividly even in the in rat poison used coumarins ). Another example is rickets and disorders of the immune and endocrine system caused by vitamin D deficiency, which also affect the mineral metabolism (cf. deficient calcium regulation in hyperparathyroidism with degradation of bone and tooth substance). A deficiency in minerals can also lead to disorders that are specific to the respective mineral (see e.g. iron deficiency , potassium deficiency , selenium deficiency ).

Oxidative cell stress

Oxidative stress causes cell damage and, according to the theory of free radicals, is not only responsible for aging , but is also linked to the development of diseases. The body's own defense system protects against damage caused by free radicals. In addition to endogenously formed antioxidants , certain micronutrients act as radical scavengers and reducing agents in the immune system . Based on the results from case control and cohort studies , there is evidence that the antioxidant vitamins C, E and the carotenoids play a role in the primary prevention of cardiovascular disease and cancer .

"Vital substances"

The term "vital substances" was introduced in 1935 by the chemist Hans Adalbert Schweigart as a collective term for chemically inconsistent substances that play a role in the metabolism . In 1954 Schweigart founded the International Society for Research on Nutrition and Vital Substances (IVG). The term was first mentioned in the IVG magazine in 1956. "Vital substances" were therefore "biologically important substances", including "in addition to water and oxygen, the carbonic acid primarily necessary for the plant , the exogenously essential amino and fatty acids, the vitamins and minerals including trace elements and [...] endogenously essential enzymes and hormones ”. In 1957 the Society's Scientific Council then defined:

“Vital substances are mainly effective vital components as biocatalysts in cells and tissues in the presence of water, oxygen and carbonic acid (the latter in plants). According to previous findings, these include: enzymes, co-enzymes , vitamins, hormones , exogenous-essential amino acids, exogenous-essential fatty acids, main and trace elements, fragrances and flavors. "

Two years later, the German Nutrition Society (DGE) criticized the term as imprecise and rejected the " dynamic nutrition theory " based on it. Nevertheless, the term is still used sporadically in the literature, especially in connection with so-called orthomolecular medicine . The definition differs from author to author. Max Otto Bruker, for example - the founder of the "whole foods rich in vital substances" - referred to vitamins, minerals, trace elements, enzymes, unsaturated fatty acids and flavorings as well as fiber as "vital substances".

The term is unsuitable for scientific use because it encompasses a large number of substances with different mechanisms of action. The Brockhaus Encyclopedia digital defines it as an "imprecise term for several groups of active ingredients (especially vitamins, essential amino and fatty acids) that are necessary for the structure and physiological functions of living cells and the entire organism".

The IVG also introduced the term “antivital substances” and understood it to mean “substances that inhibit, destroy or overwhelm the naturally secure process through undesired intervention in cellular processes.” This term did not catch on.

See also

literature

  • NIH State-of-the Science Panel: National Institutes of Health State-of-the-Science Conference Statement: Multivitamin / Mineral Supplements and Chronic Disease Prevention . In: The American Journal of Clinical Nutrition . tape 85 , no. 1 , 2007, p. 257S-264S , PMID 17209206 ( full text [accessed February 5, 2013]).
  • Bruce N. Ames: Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage . In: Proceedings of the National Academy of Sciences . tape 103 , no. 47 , November 21, 2006, pp. 17589-17594 , doi : 10.1073 / pnas.0608757103 .
  • U. Gröber: Micronutrients . Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart 2011.

Individual evidence

  1. ↑ European Food Information Council: Macro and micronutrients ( Memento from February 15, 2015 in the Internet Archive )
  2. ↑ Max Rubner Institute : Bioactive Substances in Meat? ( Memento from December 22, 2014 in the Internet Archive )
  3. ↑ German Society for Nutrition e. V .: Germany is not a vitamin deficiency country
  4. ^ Federal Institute for Risk Assessment: Health Assessment of Food Supplements
  5. ↑ Vitamins, trace elements and cancer: (Not) a plus for health? , Cancer Information Service of the German Cancer Research Center (DKFZ), Heidelberg. November 3, 2011. Retrieved September 3, 2014.
  6. ↑ Scinexx.de/ University of Rochester Medical Center (February 10, 2005): Environmental toxins increase the risk of Parkinson's disease - PCBs and pesticides make brain cells more susceptible to damage
  7. ↑ Scinexx.de/ Universität Zürich (May 22, 2007): Enzyme against cancer discovered - protective shield works against oxidative stress
  8. ↑ Takaoki Kasahara and Tadafumi Kato: A new redox-cofactor vitamin for mammals. In: Nature. Volume 422, No. 6934, 2003, p. 832, doi: 10.1038 / 422832a
    New B vitamin discovered. From: Wissenschaft.de from April 24, 2003, accessed on September 9, 2019.
  9. ↑ Monika Eichholzer: Antioxidants in the prevention of cardiovascular diseases and cancer: Epidemiological evidence. In: Swiss Journal for Nutritional Medicine (SZE) , 8 (5): 12-20.
  10. ↑ a b Jörg Melzer: Whole food nutrition. Dietetics, naturopathy, National Socialism, social demands. , Stuttgart 2003, p. 311.
  11. ^ Claus Leitzmann, Markus Keller, Andreas Hahn: Alternative nutritional forms , 2nd edition, Georg Thieme Verlag 2005; P. 167. ISBN 3-8304-5324-8 .
  12. ↑ Brockhaus Nutrition, Article Vital Substances , 2nd ed. 2004
  13. ↑ Vital substances In: Brockhaus Enzyklopädie digital , Bibliographisches Institut & FA Brockhaus AG, 2002.
  14. ↑ Jörg Melzer: Whole food nutrition. Dietetics, naturopathy, National Socialism, social demands. , Stuttgart 2003, p. 315 f.