Magnesium is essential for all cells in the body. Magnesium is a macro mineral, which means that the body needs it in large quantities, unlike trace minerals. It participates in over 300 enigmatic processes, such as protein synthesis, nucleic acids and the Krebs cycle. There is approximately 25 g of it in the adult body, of which over 50% is found in bones and about 30% in muscles.

The Function of Magnesium in the Body

Magnesium plays a role in a wide range of physiological processes that are necessary for the body's normal functioning. The main functions are:

Heart disease

Magnesium is particularly important for maintaining a normal heart rhythm and is often used in the treatment of cardiac arrhythmia, especially in patients diagnosed with congestive heart failure, a risk group prone to arrhythmia.¹
The results of studies that have studied patients who survived a heart attack and took magnesium during the recovery period are contradictory. Some have shown lower mortality, fewer arrhythmias and lower blood pressure, while others have not found these improvements.

High blood pressure

A diet low in fat dairy products and rich in vegetables is associated with lower blood pressure. These foods are also rich in magnesium, calcium and potassium. It is difficult to conclude which of these nutrients on its own has the greatest effect. Recent research published in American Heart Association Journals shows that magnesium supplementation modestly reduces blood pressure. It is most effective for individuals with hypertension, those taking blood pressure-lowering medications, or those with low magnesium status.

Stroke

Study results suggest that people with inadequate magnesium intake are at higher risk of stroke. Magnesium may be helpful in treating people who have had a stroke or who suffer from temporary disruptions in the blood supply to certain parts of the brain (transient ischemic attack).

Preeclampsia

Preeclampsia is pregnancy-induced hypertension and affects between 3 and 7% of pregnant women. It can occur during the third trimester of pregnancy and is characterized by a sudden increase in blood pressure. The exact cause is unknown. Magnesium helps in the treatment and is usually administered intravenously. The results of magnesium supplementation for the prevention of preeclampsia are not consistent.²

Diabetes

Type 2 diabetes is associated with low levels of magnesium in the blood. Several studies, including the PubMed Central Type 2 Diabetes Study, shows that a higher intake of magnesium is linked to a reduced risk of developing type 2 diabetes. Maintaining adequate magnesium levels helps improve insulin sensitivity and support overall pancreatic function. Magnesium deficiency in people with type 2 diabetes can impair immunity and make them more susceptible to infections and the development of diseases.

Osteoporosis

A deficiency of calcium, magnesium, and vitamin D is considered the main cause of osteoporosis. Adequate intake of these minerals and vitamins, along with a balanced diet and exercise, including weight training, both in early childhood and later in life, are considered primary preventive measures against the occurrence of this disease. Recent clinical study (2026) highlight magnesium deficiency as a major risk factor for osteoporosis and bone fractures.

Migraine and headache

People with severe migraines, including children and adolescents, have lower magnesium levels than people who do not suffer from migraines or headaches. Several studies even indicate that additional magnesium supplementation can shorten the duration and reduce the need for medication.
Some doctors suggest taking magnesium as an alternative to headache and migraine medications, especially for people who have contraindications to medications, heart patients, and pregnant women.

Asthma

Studies suggest that magnesium administered intravenously or by inhalation can help treat acute asthma attacks in children and adults, while oral magnesium supplements along with regular asthma medications improved lung function.³. Data from other studies show that long-term regular oral magnesium supplementation does not reduce the symptoms and frequency of asthma attacks. Research on the general population has established a connection between inadequate intake of magnesium and the occurrence of asthma in children and adults.

Attention Deficit Hyperactivity Disorder (ADHD)

According to one clinical study, 95% of children diagnosed with ADHD are deficient in magnesium. Another, also clinical study, showed that children whose therapy included magnesium showed a significant improvement in behavior, in contrast to a control group that took only standard therapy and whose condition even worsened.
Study results indicate that magnesium supplementation may be beneficial for children diagnosed with attention deficit hyperactivity disorder

Infertility and abortion

a small clinical study in infertile women and women who had a miscarriage linked low magnesium levels to reduced reproductive function and an increased risk of miscarriage. Studies suggest the inclusion of magnesium (and selenium) supplementation in infertility treatment.

PMS

Clinical experience suggests that taking magnesium can relieve symptoms associated with PMS, particularly bloating, insomnia, leg swelling, breast tenderness, and weight gain. Preliminary information indicates that magnesium may affect less sudden mood swings.

Recommendations for intake

The recommended daily intake of magnesium in the EU is set at 375 mg per day, while in the USA it is set at 400-420 mg for men and 310-320 mg for women. Research shows that the recommended daily intake of magnesium in most European countries, but also in the USA, is below the recommended daily intake, when it comes to the intake of common forms, such as magnesium oxide.

Magnesium deficiency

Although the amounts of magnesium taken in food are below the recommended daily values, severe symptoms of deficiency are relatively rare. Certain health problems can cause a serious magnesium deficiency. Intestinal viruses with vomiting and diarrhea can cause a temporary deficiency. Intestinal and stomach diseases, diabetes, pancreatitis, kidney dysfunction and the use of diuretics can significantly endanger the necessary amounts of magnesium in the body.
Too much coffee, carbonated drinks, salt and alcohol, heavy menstruation, intense sweating and prolonged stress can reduce magnesium levels.
Symptoms of deficiency may include agitation and anxiety, restless legs syndrome, sleep disturbances, irritability, nausea and vomiting, abnormal heart rhythm, low blood pressure, confusion, muscle weakness and spasms, and hyperventilation.

Natural sources

The best natural sources of magnesium are tofu, legumes, leafy green vegetables, wheat bran, soy flour, almonds, cashews, pumpkin and pine nuts, oatmeal, bananas, chocolate (with more cocoa)
Leafy green vegetables are especially recommended since they contain a lot of chlorophyll in which magnesium is the central atom.

Which form of magnesium should I choose as a dietary supplement?

There are numerous forms of magnesium available on the market, the most famous of which are magnesium citrate, magnesium bisglycinate, magnesium L-threonate, magnesium malate, magnesium oxide or hydroxide. Although they all serve as a source of magnesium, they differ in their characteristics, elemental magnesium content, and purpose.

In recent years, products that combine multiple forms of magnesium in a single capsule or tablet have become increasingly popular. Such products may sound attractive, but more important than the number of different compounds is how much elemental magnesium you get and in what amounts each form is found. More forms in one capsule does not necessarily mean more efficiency.

When choosing a food supplement, it is advisable to pay attention to the composition of the product, the amount of elemental magnesium, and your own needs and lifestyle. Read more about the differences between the most common forms of magnesium in a separate article.

Safety of taking magnesium as a dietary supplement

Taking too much magnesium from supplements can cause diarrhea. People with impaired kidney function are at risk and should be careful.
High blood magnesium levels can cause a drop in blood pressure (hypotension). Later signs of magnesium poisoning such as lethargy, confusion, heart rhythm disturbances, and deterioration of normal kidney function are associated with severe hypotension.

The European Food Safety Authority (EFSA)† has approved the following health claims for magnesium:

References

1.) The Connection Between Magnesium and Heart Health: Understanding Its Impact on Cardiovascular Wellness ; Siddiqui, Nishat, Alzaabi et.al.: (Cureus. 2024 Oct 24)
2.) Oral Magnesium Supplementation for the Prevention of Preeclampsia: a Meta-analysis or Randomized Controlled Trials; Yuan, Yu, Zhu et.al. (Epub 2021 Nov 13.)
3.) A Randomised Controlled Study on Effect of Oral Magnesium Supplements in Control of Symptoms of Bronchial Asthma and Lung Function Parameters; Yanamadala Rowhit (European Respiratory Journal 2021)