Selenium (Se) is an essential trace mineral found in soil, water, and some foods [1] [2] [3]. In humans, selenium functions as a cofactor for the antioxidant enzymes, including glutathione peroxidase, whose main role is to protect organisms from oxidative damage, and some thioredoxin reductases, which are essential for cell growth and survival [4].

National Nutrition Study

Selenium was not covered in the german national consumption survey, but there is data from other European countries (Denmark, Finland, Italy, Netherlands and Sweden) available.
  • 60% of the adult population does not reach the recommended daily allowance of Selenium [9].

Function of Selenium

Selenium is a major part of the body’s protective system in a complex interaction with catalases, superoxide dismutase, GSH-Transferase and antioxidants like Vitamin E and C [5] [6] [7].
The mineral is an antioxidant and helps to protect the body from free radicals [5] [8] .
Selenium is necessary for the activation of the thyroid hormone T3, which heavily influences the growth and metabolism of the body [5] [6].

Deficiency Symptoms

The early signs of a Selenium deficiency are muscle weakness and the degeneration of muscles [5] [6].
Another sign for Selenium deficiency is chronic inflammations [6].
A severe long-term deficiency can lead to the Keshan-Illness, which manifests itself as a change of size of the heart and heart failure, or to the Kashin-Beck-illness, which manifests itself as the degeneration or formation of joints [5] [6].

Surplus of Selenium

A surplus of Selenium can lead to the storage of Selenium heavy metal complexes in the inner organs [5].
An increased Selenium intake in combination with an Iodine deficiency can lead to in imbalance in the thyroid function, which in turn can alter the metabolic rate [5].
A severe oversupply of Zinc can lead to change of skin and in some rare cases to liver damage [7].

[1] Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at:

[2] Apostolidis, N. S., Panoussopoulos, D. G., Stamou, K. M., Kekis, P. B., Paradellis, T. P., Karydas, A. G., Zarkadas, C., Zirogiannis, P. N., and Manouras, A. J. Selenium metabolism in patients on continuous ambulatory peritoneal dialysis. Perit.Dial.Int 2002;22(3):400-404. (Abstract:

[3] Aberg, B. [Selenium as a trace element]. Nord.Med 5-26-1966;75(21):589-593. (Abstract:

[4] Schrauzer GN. Nutritional selenium supplements: product types, quality, and safety. J Am Coll Nutr 2001;20:1-4. (Abstract:

[5] Koula-Jenik, H., Miko M., Kraft M., Schulz R., Leitfaden Ernährungsmedizin. Elsevier,Urban&Fischer Verlag 2013;p.68-70

[6] Biesalski HK., Muniz K., Vitamine und Minerale: Indikation, Diagnostik, Therapie. Thieme Verlag 2017; p.140

[7] Wibusch N, Hofmann P, Förster H, Hörtnagl HLedl-Kurkowski E, Pokan R, Kompendium der Sportmedizin Physiologie, Innere Medizin und Pädiatrie. Springer-Verlag 2016; p. 354

[8] Christoph Raschka, Stephanie Ruf, Sport und Ernährung: Wissenschaftlich basierte Empfehlungen, Tipps und Ernährungspläne für die Praxis. Georg Thieme Verlag 2015; p.132

[9] Vinas BR et al. Projected prevalence of inadequate nutrient intakes in Europe. Ann Nutr
Metab 2011; 59: 84–95

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