Minerals Part I: Calcium and Magnesium

In order to be able to easily classify the variety of substances to be ingested daily, let us first look at their classification. Proteins and carbohydrates belong to the so-called macronutrients, which serve to produce energy. Substances that also need to be consumed regularly, but not for energy production, are so-called micronutrients. These include the vitamins already described as well as the minerals that are now the focus of attention.

Calcium and magnesium in a few minutes:

• Both magnesium and calcium belong to the bulk elements. Consequently, 300 to 400 mg of magnesium and about 1,000 mg of calcium should be taken in daily.
• Both elements are mainly found in the bones. 65 % of the total amount of magnesium and 99 % of calcium are stored in this way
• Magnesium is often a cofactor for enzymes and ensures that these substances work properly. In addition, magnesium reduces neuromuscular excitability and thus ensures proper functioning of the muscles. Magnesium is also involved in the .
• Calcium has a variety of functions in the body: it is part of signal transmission chains, ensures the release of transmitters at synapses, mediates muscle contraction, stabilises the membrane potential of cells, plays an important role in blood clotting and is also involved in the formation of bones and teeth.
• It is important to ensure an optimal supply of both minerals. If there is an excess or insufficient supply, there is a risk of a large number of symptoms with consequences that should not be underestimated.

Minerals are divided into trace and bulk elements.

These so-called minerals can be further divided into trace and bulk elements. Trace elements fall below the limit of 50 mg per kilogram of body weight within the scope of the daily necessary intake, whereas the bulk elements exceed this value. Since minerals include numerous substances, the following content deals with the two representatives calcium and magnesium.

Magnesium is one of the bulk elements

The German Nutrition Society recommends a daily magnesium intake of 300 to 400 mg. In terms of definition, magnesium is one of the bulk elements. Since magnesium occurs in a positively charged state, this element belongs to the electrolytes. In the body, 65% of magnesium is found in our bones. It should be mentioned that magnesium is the least abundant mineral in the entire body, with about 24 grams. Sunflower seeds, nuts and sprouts are particularly good sources.

Magnesium has three essential functions

With regard to the functions of magnesium, there are three essential core areas:

1. Magnesium often acts as a cofactor for the proper functioning of various enzymes
2. Another main competence is the reduction of neuromuscular excitability
3. It should not be forgotten that magnesium plays a major role in the formation of teeth and bones.

A magnesium deficiency often leads to neuromuscular disorders, even tetany. This means that the person affected suffers from tingling or cramps because the muscles are over-excited. This is exactly the reason why magnesium is used prophylactically in the context of calf cramps.

But too high a magnesium level can also lead to sensitive symptoms such as nausea, constipation, muscle weakness or heart problems. If the serum level is even abnormally high, respiratory / cardiac arrest or paralytic ileus (intestinal movement fails) can occur. A magnesium deficiency may be caused by a lack of magnesium intake or absorption in the small intestine. In fact, a deficiency is often associated with liver disease. Excess magnesium, on the other hand, is often associated with diabetes and renal insufficiencies.

Calcium is also a bulk element

Since the German Nutrition Society recommends a minimum daily intake of about 1,000 mg, calcium is also one of the so-called bulk elements. Calcium is also a positively charged ion, which is why calcium counts as an electrolyte. 99% of all calcium is found bound with phosphate in the bone. With a total amount of about one kilo in the body, calcium, unlike magnesium, is the most abundant mineral. Milk and dairy products as well as mineral water are good sources.

Calcium fulfils a variety of functions in the body

The bulk element has a wide variety of tasks in our organism. Calcium is often part of signal transmission chains in which calcium acts as a second messenger. For example, calcium is responsible for the release of transmitters at synapses. Furthermore, calcium plays a prominent role in muscle contraction. It also stabilises the membrane potential, which is why the smallest fluctuations in concentration can have serious consequences in the body.

To illustrate further functions, it should be mentioned that calcium is active as a coagulation factor in the way of blood coagulation and is significantly involved in the formation of teeth and bones. The calcium balance is dependent on numerous organs and hormones. If the calcium level in the body drops, the parathyroid hormone ensures that more calcium is released from the bones. Vitamin D also plays an important role in calcium balance. The vitamin ensures that more calcium is absorbed in the intestines and kidneys and incorporated into the bones. Finally, we should mention calcitonin, which is produced in the thyroid gland and acts as an antagonist of the parathyroid hormone. It ensures that calcium is released from the bones in reduced amounts, thus lowering the calcium level.

Too much and too little calcium leads to a wide range of symptoms.

Since calcium performs significant and numerous functions, an optimal calcium level is necessary. In the case of an excess, there is a variable expression of symptoms. Frequent symptoms include cardiac arrhythmia, paresis (= paralysis), muscle weakness, constipation, polyuria (frequent urination), nausea, pancreatitis (= inflammation of the pancreas) or neurological symptoms such as depression and anxiety disorders. In the case of calcium deficiency, the symptoms are clearer. A deficiency can be easily diagnosed with the so-called leading symptom of tetany and the consequence of muscle tingling, pawing of the hands and hyperexcitability of the reflexes. In addition, cardiac, neurological and gastrointestinal problems can occur.

Text sources:

(1) Liu et al., Magnesium and liver disease, 2019

(2) https://www.dge.de/wissenschaft/referenzwerte/magnesium/

(3) https://www.dge.de/wissenschaft/referenzwerte/calcium/

(4) Rassow et al., Biochemistry, 4th edition, 2016

(5) Biesalski et al., Nutrition, 8th edition, 2020

(6) Lüllmann et al, Pharmacology and Toxicology, 18th edition, 2016.

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