Selenium: deficiency symptoms
Because of the large differences in the selenium content of soils, the selenium content in crops varies greatly. In many regions of Europe, including Germany, soils contain only a small amount of selenium - due in part to sulfur dioxide-laden acid rain and sulfur-containing fertilizers (sulfur is then taken up by plants instead of selenium). The trace element is therefore often added to the cattle feed, as the animals are less susceptible to disease.
Animal proteins are better sources of selenium
Animal proteins are usually better sources of selenium than vegetable foods because of the selenium poor soils. Some scientists classify Germany as a selenium deficiency area, because often the actual selenium intake - on average 30-60 μg / day - falls short of the recommendation of the German Nutrition Society (DGE).
Selenium deficiency: Causes and Affected
Affected by a selenium deficiency are in many cases people who take on the one hand with their diet little selenium: These include people who only feed on vegetable protein, poorly-cared old people, in alcohol abuse, people with a one-sided diet, with feeding patients and patients dialysis patients.
On the other hand, a selenium deficiency can occur when selenium is excreted: This can happen with long-lasting diarrhea, but also via the urine in diabetes mellitus or severe kidney disease. Gastrointestinal diseases (eg chronic inflammatory bowel diseases such as ulcerative colitis) can lead to a disturbed selenium intake. An increased need for selenium can exist during pregnancy, during heavy menstrual bleeding and during breastfeeding. Even with cancer, the body "consumes" more selenium.
Consequences of lack of selenium
The consequences of selenium deficiency have not yet been fully explored. In extreme selenium deficiency areas of China and Central Russia, the most severe cardiac muscle diseases and diseases of the joints have been observed. However, it is still unclear whether this so-called. Kashin-Beck disease is actually the result of selenium deficiency or other triggers.
Recent studies also suggest a link between low levels of selenium and high blood pressure, disorders of lipid metabolism and the development of arteriosclerosis. There is also evidence that selenium deficiency can affect fertility: women who suffered abortions had extremely low blood levels of the trace element. In men with a selenium deficiency, the maturation and motility of sperm may be disturbed.
Overdose of selenium
Selenium in higher concentration has toxic effects. Normally, therefore, the body excretes excess selenium with the urine. However, if larger amounts are regularly supplied over a longer period, for example via dietary supplements, complaints can occur. These include hair loss, liver damage, nerve disorders and myocardial insufficiency.