Magnesium overdose and its symptoms

Every athlete, whether professional or enthusiastic amateur, knows magnesium. It's almost a magic word, synonymous with fighting cramps, promoting recovery and proper muscle function. The shelves in pharmacies and sports nutrition stores sag under dozens of different forms of this mineral.

In the pursuit of better performance and faster recovery, it's easy to succumb to the "the more the merrier" mentality. But scientific studies and clinical practice show that even this indispensable helper can become a dangerous adversary. Magnesium overdose, known professionally as hypermagnesaemia, is a rare but all the more insidious condition that can have fatal consequences. So in this article, we will look at where the limits of safe use lie and what symptoms should never be ignored, based on the literature.

Article content:

• An indispensable engine for the body
• Hypermagnesaemia: When the kidneys can't keep up
• Clinical manifestations: from nausea to cardiac arrest
• Treatment and prevention: respect and awareness are key

An indispensable engine for the body

Before we delve into the darker side of magnesium, it's fair to highlight its crucial role. Magnesium (Magnesium, Mg) is the fourth most abundant cation in our body and is involved in more than 300 enzymatic reactions. For athletes, its most important functions are in:

• Muscle contraction and relaxation: a proper balance between calcium and magnesium is crucial for smooth muscle movement. While calcium stimulates contraction, magnesium acts as its natural counterpart and allows the muscle to relax. Its deficiency leads to the infamous cramps.
• Energy production: magnesium is essential for the production and use of the cell's basic energy unit, adenosine triphosphate (ATP). Without it, our muscles simply would not have "fuel".
• Nervous system: It stabilizes nerve cells and regulates the transmission of nerve impulses. This contributes to mental well-being and a reduction in fatigue and exhaustion.
• Bone health and protein synthesis: It plays a role in calcium metabolism and is essential for building new proteins, which is the basis for repair and growth of muscle tissue after training.

No wonder magnesium supplementation is so popular. The problem arises when the natural reverence for this element is replaced by mindless consumption.

Hypermagnesaemia: When the kidneys can't keep up

Fortunately, our bodies have a very effective mechanism to deal with excess magnesium - healthy kidneys. They can efficiently filter out excess magnesium and excrete it from the body in the urine. This is why an overdose from a normal diet is virtually impossible in a healthy person. The risk rises dramatically in people with impaired kidney function because their ability to regulate mineral levels is limited.

However, even a person with healthy kidneys can break through this line of defence, especially through the massive and indiscriminate use of dietary supplements, often in combination with magnesium-containing drugs (e.g. some laxatives and antacids for heartburn).

Treatment and prevention: respect and awareness are key

Treatment of acute magnesium overdose belongs exclusively in the intensive care unit. The first step is to stop the magnesium supply immediately. As a specific antidote (antidote), calcium is given in intravenous form. Calcium acts as a direct antagonist of magnesium and can quickly reverse its depressant effects on the heart and muscles. Furthermore, the excretion of magnesium from the body is promoted by diuretics and in the most severe cases or in renal failure, dialysis ('artificial kidney') is necessary.

For us athletes, however, prevention is the most important thing. So how to approach magnesium responsibly?

1. Know your needs: the recommended daily dose of magnesium for an adult male is around 400-420 mg, for a woman 310-320 mg. Athletes may have a need 10-20% higher.
2. Read the ingredients: watch out for the accumulation of magnesium from multiple sources. You may be unknowingly ingesting it in a multivitamin, for example.
3. Do not exceed the recommended dosage: Follow the manufacturer's instructions. Doses above 350 mg of elemental magnesium from supplements per day should be consulted with a specialist.
4. Listen to your body: If you observe nausea, diarrhea (the most common mild side effect) or any of the symptoms described above after supplementation, stop taking the supplement immediately and seek medical attention.

Magnesium is and will remain one of the most important minerals for health and athletic performance. It is a great servant that helps our bodies function at full capacity. However, this article shows that if we lose respect for its power and start taking it indiscriminately, it can turn into a bad master very quickly. The key, as with everything else in sport and life, is balance and awareness.

Sources:

• [1] R. G. Graber, "Neurological manifestations of hypermagnesemia," The Neurohospitalist, vol. 3, no. 1, pp. 41-44, Jan. 2013.
• [2] K. M. L. Leong, N. G. R. Bee, and L. K. T. Ng, "Iatrogenic magnesium overdose: two case reports," Journal of the Royal Society of Medicine, vol. 93, no. 3, pp. 136-137, Mar. 2000.