Magnesium overdose

Magnesium is an essential mineral that is involved in over 300 biochemical reactions in the human body. It is crucial for energy metabolism, supports heart and muscle function, and strengthens bones. Magnesium is typically found in nature bound to other elements, which explains the wide range of magnesium supplements available. In our article on magnesium deficiency, we have already shown you how to recognize a deficiency and which magnesium-rich foods can help you compensate for a deficiency. But what happens in the rarer case of a magnesium overdose? How can you recognize a magnesium overdose and what symptoms are associated with it? We will examine these questions in more detail in this article.

What is a magnesium overdose?

A magnesium overdose, also known as Hypermagnesemia, occurs when the concentration of magnesium in the blood exceeds the normal range. True to the motto, the dose makes the poison. The limits that indicate a magnesium excess, are more than 1,00 mmol/L (2,2 mg/dL).

This phenomenon is relatively rare and occurs most frequently in people with impaired renal function or from taking excessive amounts of magnesium supplements. Because magnesium plays a crucial role in many body processes, including muscle and nerve function and heart rhythm, excess can lead to a range of symptoms and health problems.

Symptoms of a magnesium overdose

The symptoms of a magnesium overdose can be varied and often depend on the severity of the overdose. The most common symptoms include:

• Muscle weakness and muscle pain: Excessive magnesium levels can impair muscle contraction, which can lead to weakness and pain.
• Neurological disorders: These include lethargy, dizziness and, in severe cases, even impaired consciousness.
• Arrhythmia: Magnesium affects the electrical activity of the heart, and excess can lead to arrhythmias.
• Low blood pressure: Magnesium has a vasodilating effect, which can lower blood pressure.

Background: The role of the kidney in hypermagnesemia

Impaired kidney function can lead to hypermagnesemia, i.e. an increased magnesium level in the blood, as the kidneys play a central role in regulating magnesium levels in the body. Normally, the kidneys filter magnesium from the blood and reabsorb most of it back into the body, while the rest is excreted in the urine. This finely tuned balance ensures that magnesium levels in the body remain within a healthy range.

Role of the kidneys in magnesium regulation

The kidneys regulate magnesium levels in the body through two main processes:

1. Filtration: Magnesium is filtered along with other electrolytes and fluids through the glomeruli, the filtering units of the kidneys.
2. Reabsorption: A large part of the filtered magnesium is reabsorbed back into the body in the tubules, the small tubes of the kidneys. The fine-tuning of magnesium reabsorption occurs mainly in the thick ascending limb of the loop of Henle and in the distal tubule.

Effects in case of impaired renal function

When renal function is impaired, the kidneys’ ability to efficiently filter and reabsorb magnesium is impaired. This leads to less magnesium is excreted in the urine and instead accumulates in the blood, which can lead to hypermagnesemia.

TRPM6 in the kidney

Reabsorption of magnesium in the kidneys is a complex process mediated by various transporters and channels, including:

• TRPM6: This channel plays a crucial role in magnesium reabsorption in the distal convoluted kidney. In cases of impaired renal function, the expression or function of TRPM6 may be impaired, disrupting magnesium reabsorption.
• Paracellular transport: In the thick ascending limb of the loop of Henle, magnesium reabsorption occurs mainly via a paracellular pathway that depends on the electrical charge difference across the tubular wall. Disturbances in this area can also lead to reduced reabsorption and thus to hypermagnesemia.

Did you know?

TRPM6 and TRPM7 are members of the Transient Receptor Potential Melastatin (TRP) channel familythat play an important role in regulating magnesium homeostasis in the body. These channels are crucial for the Absorption of magnesium in the intestine and reabsorption in the kidneys, which makes a significant contribution to maintaining magnesium balance. TRPM6 is found almost exclusively in the kidneys and intestines, while TRPM7 is expressed in many different body cells. If you want to know more about these transporters and the factors that regulate them, you will find the answer in our article on Magnesium in food.

Magnesium overdose and the thyroid

Although a direct link between magnesium overdose and thyroid function is rarely discussed, magnesium plays a role in metabolism and could potentially affect thyroid hormone production. In this Study It was investigated whether regular administration of magnesium, Vitamin A and Zinc would lead to an improvement in symptoms. BIn the participants, the supplementation increased the amount of thyroid hormones (FT4) and the inflammatory parameters (hs-CRP) were lower.

The parathyroid gland and magnesium.

The parathyroid gland is located – as the name suggests – next to or on the thyroid gland. It produces the parathyroid hormone, which plays an important role in Calcium-balance. An overdose of magnesium can affect this cycle, but a magnesium deficiency is much more common.

Hypomagnesemia and parathyroid hormone

• Parathyroid hormone secretion: Magnesium is necessary for the secretion of parathyroid hormone by the parathyroid glands. Parathyroid hormone is a hormone that plays an important role in regulating calcium and phosphate levels in the body. When magnesium levels are low, the secretion of PTH can be inhibited, which in turn impairs the body's ability to regulate calcium levels in the blood.
• PTH effect: Even if parathyroid hormone is released in the presence of magnesium deficiency, magnesium deficiency can reduce the effectiveness of PTH on the bones and kidneys. Magnesium is required for the normal response of these tissues to PTH. Without adequate magnesium, the bones are less able to release calcium effectively and the kidneys are less able to reabsorb calcium, resulting in lower calcium levels.

Hypomagnesemia and hypocalcemia

• Direct effect on calcium levels: Inhibition of PTH secretion and action by magnesium deficiency leads directly to hypocalcemia. Since PTH is critical for maintaining calcium homeostasis, reduced PTH activity leads to inadequate calcium release from bone, reduced calcium absorption from the intestine, and reduced calcium reabsorption in the kidneys.
• Long-term effects: In the long term, persistent hypomagnesemia associated with hypocalcemia can lead to bone weakness and an increased risk of osteoporosis.

Treatment and management

Treatment of hypomagnesemia and associated hypocalcemia includes Correction of magnesium deficiency, often through oral or intravenous magnesium supplementation. In many cases, restoring normal magnesium levels will normalize PTH levels and correct hypocalcemia. It is important to identify and address the underlying causes of magnesium deficiency to prevent recurrence.

Did you know?

The research interest in the role of Magnesium in relation to longevity has initiated the extensive ROADMAP study which will continue until 2024 and whose results are still pending. This study focuses on how Magnesium in combination with calcium and phosphate is involved in arteriosclerosis. An imbalance of these minerals can lead to accelerated calcification of the blood vessels. The research team is investigating the effects of supplementation with Magnesiumcitrat, both with and without the addition of a phosphate binder, on the flexibility of the arteries and the reduction of calcification. The aim is to determine whether adjusting the mineral balance can improve vascular health and thus potentially promote longevity.

What happens if you overdose on magnesium during pregnancy?

During pregnancy, a magnesium overdose can pose risks for both the mother and the unborn child. Magnesium supplements are often used to treat or prevent certain pregnancy complications, but excessive intake can lead to symptoms similar to those described above. This includes muscle weakness, neurological disorders and cardiac arrhythmias. Careful monitoring and adjustment of magnesium intake is therefore particularly important during pregnancy to avoid both deficiency and overdose. We will discuss this aspect in more detail in the article. Magnesium in pregnancy .

Treatment of magnesium overdose

Treatment of magnesium overdose focuses on reducing magnesium levels in the blood. In mild cases, stopping taking magnesium supplements may be enough. In more severe cases or in patients with impaired renal function, medical interventions may be necessary, such as intravenous calcium, which acts as an antagonist to magnesium, or in extreme cases, dialysis.

Conclusion

Magnesium overdose is rare but can cause serious health problems, including muscle pain, neurological symptoms, and abnormal heart rhythm. Special care is required in people with impaired renal function and during pregnancy. Appropriate monitoring and dosed intake of magnesium can help minimize the risk of overdose.