Manganese

Manganese is a gray, very hard but brittle base metal. It has the atomic number 25 in the periodic table of the elements and the chemical symbol Mn. Manganese was already used in cave paintings in the form of brownstone. It was first extracted from manganese dioxide and coal in 1774 by the Swedish chemist Johann Gottlieb Gahn (1745-1818). It is the 14th most abundant element in the Earth's mantle. Pure manganese does not occur on earth, it is mainly found as manganese dioxide (MnO2) or as manganese sulfide (MnS). Manganese is of particular technical importance as an additive in steel production. Because of their hardness, durability and heat resistance, such manganese steels are used, for example, in rail construction, tapping or forging tools. Manganese is an essential trace element for humans. The body needs it for bone growth, and it is also involved in the formation of various enzymes. The human body contains about 10 to 40 mg of manganese. Of this, about 40 percent is found in the bones. Furthermore, manganese is found in the liver, kidneys, pancreas, muscles and hair pigments.

Functions in the body

Manganese is significantly involved in some important processes in the human body, in that the trace element is indispensable for the function of various enzymes. For example, manganese is involved in the formation of cartilage and bone tissue. It activates the enzyme glycosyltransferase, which is involved in proteoglycan synthesis (chondroitin sulfate) in cartilage and bone. By activating pyruvate carboxylase, manganese also participates in gluconeogenesis, i.e. the formation of new glucose. Furthermore, manganese activates the enzyme arginase, which plays a role in the urea cycle, and pancreatic enzymes, which are involved in the breakdown of protein building blocks (amino acids). Furthermore, manganese is required for the synthesis and release of insulin. It is involved in blood clotting via the production of prothrombin. With ATP (adenosine triphosphate), manganese can form an Mn-ATP complex and act as a cofactor instead of magnesium. ATP is the key substance in biological energy transfer. Manganese is further involved in the production of melanin (pigments) and dopamine (neurotransmitter). It also activates a number of enzymes that, for example, act as antioxidants (Mn superoxide dismutase) and are important for the utilization of vitamin B1 (phosphatase).

Manganese in food

Apart from a few exceptions, such as snails and offal, animal foods in principle contain less manganese than plant foods.

Some cereal products are particularly rich in manganese, e.g. oatmeal, wheat germ and soy flour. Of the vegetables, soybeans, garlic and white beans stand out for their higher manganese content. Among fruits, pineapple, blueberries and raspberry juice are particularly high in manganese. Furthermore, nuts, chocolate and some spices, such as cinnamon, ginger, black pepper and ground cloves contain high amounts of manganese.

Manganese-rich foods contain per 100 g about:

• Rice 1.1 mg
• Millet 1.9 mg
• Whole wheat bread 2.5 mg
• Hazelnuts 3 mg
• Whole wheat flour 3.5 mg
• Wheat bran 3.7 mg
• Soy flour 4 mg
• Oatmeal 4.5 mg

3.5 mg manganese (average daily requirement) is contained approximately in:

• 75 g oatmeal
• 95 g wheat bran
• 115 g cereals
• 140 g whole wheat bread
• 175 g legumes
• 320 g rice or rye bread
• 1200 g fish, meat, cheese or cottage cheese

Deficiency symptoms

The concentration of manganese can be determined in the blood, which normally ranges between 7.0-10.5 µg/l in whole blood and 0.3-1.1 µg/l in blood serum. Undersupply of manganese does not occur very frequently, so some symptoms of manganese deficiency have so far only been observed in animals. In ruminants, for example, manganese deficiency leads to lipid metabolism disorders, which manifest themselves in the form of hypocholesterolemia, i.e. a reduced cholesterol concentration. Furthermore, weight loss, growth disorders, osteoporosis and dysfunction of the reproductive organs have been observed in animals. Furthermore, there are coagulation disorders due to a prolonged prothrombin time and disorders of carbohydrate metabolism. Furthermore, cartilage or bone deformations may occur.

Overdose and poisoning

Overdoses with manganese are observed extremely rarely. However, workers in the mining industry have been known to suffer from manganese oxide (manganese dioxide) poisoning. Furthermore, workers in the manganese processing industry as well as steel workers may suffer from manganese poisoning. For this reason, manganese poisoning is also an occupational disease requiring compensation in the occupational groups at particular risk.

Acute poisoning leads to severe pneumonia (lung inflammation). Chronic poisoning results in encephalitis (meningitis), which is manifested by Parkinson's-like symptoms. Tremor, muscle stiffness, and disturbances in concentration and memory occur. Particularly characteristic of Parkinson's symptomatology is tremulous writing, in which what is written becomes smaller and smaller. The treatment of manganese poisoning is usually only symptomatic, i.e. only the symptoms and not the causes are treated. In the case of chronic poisoning, the Parkinson's drug levodopa can be given.

Demand

According to the recommendation of the German Nutrition Society, the manganese requirement is 1 to 2 mg daily for children under 7 years of age, and 2 to 5 mg daily for older children, adolescents and adults. Normally, it can be assumed that a balanced diet covers the manganese requirement. However, various factors can lead to a manganese deficiency:

An increased need for manganese can result from poor nutrition, for example when large amounts of simple carbohydrates (sugar) are consumed. Furthermore, manganese requirements may be increased in the case of prolonged artificial (parenteral) nutrition. Alcoholics also frequently have an increased requirement. Furthermore, increased intake of other minerals, such as calcium, iron, phosphate and zinc, can lead to manganese deficiency. The reason for this is that the minerals interfere with each other during absorption. Increased oxidative stress (increased occurrence of highly reactive oxidants, i.e. free radicals) can also possibly lead to an increased manganese requirement.

Demand in sport

3-5mg a day with meals.

Safety and side effects

Manganese is probably safe and harmless for most adults in amounts up to 11 mg per day. Excessive manganese intake can cause serious side effects including symptoms reminiscent of Parkinson's disease, such as tremors. People who have problems excreting manganese, such as those with liver disease, may experience side effects even if they take less than 11 mg of manganese per day. The amount of manganese that is safe and harmless for children depends on their age. Before giving manganese to children, you should talk to your doctor.

Precautions and warnings

Pregnancy and Lactation: Manganese is probably safe and harmless for pregnant and lactating women over 19 years of age when using dosages below 11 mg per day. Pregnant and lactating women under 19 years of age should limit the manganese dosage used to less than 9 mg per day. Manganese may not be safe and harmless when used in higher amounts during pregnancy and lactation.

Chronic liver diseases: People who suffer from chronic liver diseases have problems excreting manganese. In these people, manganese can accumulate in the body and cause tremors, mental problems such as psychosis, and other side effects. For this reason, people who suffer from liver diseases should be careful not to consume too much manganese.

Iron Deficiency Anemia: People who suffer from iron deficiency anemia seem to absorb more manganese than other people. If you suffer from this condition, you should be careful not to consume too much manganese.

Drug interactions

Care should be taken when combining manganese with the following medications:

Antibiotics (Quinolone antibiotics)

Manganese could reduce the amount of quinolone antibiotics that the body can absorb. Taking manganese in combination with quinolone antibiotics could reduce the effectiveness of quinolone antibiotics. To avoid this interaction, manganese supplements should be taken at least one hour after quinolone antibiotics.

Antibiotics (Tetracylin antibiotics)

Magan can bind to tetracyline antibiotics in the stomach. This reduces the amount of tetracyline antibiotics that the body can absorb. Taking manganese in combination with tetracyline antibiotics could reduce the effectiveness of tetracyline antibiotics. To avoid this interaction, manganese should be taken two hours before or four hours after taking tetracyline antibiotics.