Complément alimentaire magnésium

Magnesium is an essential mineral that the body cannot produce on its own. Therefore, it must be supplied daily through diet, or through a dietary supplement in cases of increased needs.

Magnesium plays a fundamental role in the functioning of the human body, with its many benefits. It notably contributes to reducing fatigue, to normal muscle function, and to maintaining normal bones.

However, despite its importance, it is one of the most frequently under-consumed nutrients in industrialized countries. An unbalanced diet, significant stress, or intense physical activity can increase the need for this mineral.

What is magnesium?

Magnesium is an essential mineral that has numerous functions in the body. Naturally present in the human body, it participates in many reactions in the body. Its role is both structural, particularly in bones, and functional, as it is involved in the functioning of muscles, the nervous system, and even our energy metabolism.

Unlike some vitamins or hormones, the body cannot produce magnesium on its own. Therefore, it must be supplied daily through diet, or through supplementation if intake is insufficient.

Where is magnesium found in the human body?

An adult contains an average of 25 grams of magnesium throughout their body. Its distribution is as follows:

• 50 to 60% is stored in the bones, where it contributes to maintaining normal bones, like calcium and phosphorus.
• Approximately 25% is found in the muscles, where it contributes to normal muscle function.
• The rest is present in various organs and soft tissues: liver, kidneys, brain, heart, etc.

Is magnesium naturally present in our body?

This essential mineral is naturally present in the human body because it is primarily stored in bones and muscles. But its maintenance relies on a dynamic balance between several processes:

• Intestinal absorption, which depends on dietary intake and the form of magnesium consumed.
• Storage, mainly in bones and muscle tissues.
• Elimination, primarily via the kidneys, through urine.

This system works relatively stably in many people, but several factors can disrupt this balance:

• A diet poor in magnesium-rich foods (legumes, oilseeds, green vegetables, whole grains).
• Significant stress, which increases urinary excretion of magnesium.
• Intense physical activity, common among athletes, which increases losses through sweat and urine.

Recommended magnesium intake according to ANSES

To ensure good physiological balance, it is essential to follow the recommended nutritional intake of magnesium. In France, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) defines these references.

• Recommendations for adults

According to the report updated in 2025 by ANSES (2), the adequate intake (AI) of magnesium for adults is as follows:

- Adult men: 380 mg per day,
- Adult women: 300 mg per day.

These intakes cover physiological needs to maintain essential body functions.

Magnesium benefits: Essential physiological role

Magnesium is a key player in many functions of the human body. This mineral has many benefits, and its adequate intake is essential to ensure good physiological balance.

• Magnesium contributes to electrolyte balance,
• Magnesium contributes to normal psychological functions,
• Magnesium contributes to the maintenance of normal bones,
• Magnesium plays a role in the process of cell division.

Magnesium and athletes: an essential ally

Magnesium plays a particularly interesting role in athletes, whether amateur or professional.

Why is magnesium important for athletes?

During physical exertion, the body intensely mobilizes its muscular and energy resources. Magnesium is involved in many essential functions:

• It contributes to the normal functioning of the nervous system,
• It helps to reduce fatigue,
• It contributes to normal muscle function,
• It plays a role in energy metabolism.

In addition, magnesium participates in normal protein synthesis, where proteins contribute to the maintenance and gain of muscle mass, which is essential for many athletes.

Increased needs in athletes

Athletes often have higher magnesium needs than the general population, due to several factors:

• Increased losses through sweat and urine, especially during intense or prolonged efforts.
• Increased energy demand linked to the intensity and frequency of training.

How to optimize magnesium intake in athletes?

To meet these specific needs, several strategies can be implemented:

• Balanced diet: prioritize foods naturally rich in magnesium, such as green vegetables (spinach, broccoli), oilseeds (almonds, walnuts), legumes (lentils, chickpeas), and whole grains.
• Adequate hydration: consume beverages containing this mineral, such as electrolyte drinks.
• Targeted supplementation: when diet is insufficient, a magnesium-based dietary supplement may be considered. It is advisable to choose well-assimilated forms such as magnesium bisglycinate or magnesium citrate.

However, it is essential to consult a healthcare professional or a sports nutritionist before starting supplementation.

Magnesium and diet: what foods are naturally rich in it?

It is important to know which foods contain magnesium. A balanced and varied diet can, in many cases, cover a good part of daily needs. But you still need to know where to look for this precious mineral.

The best dietary sources of magnesium

Magnesium is present in many foods, especially those of plant origin. Here is a non-exhaustive list of the richest foods in magnesium:

Tip: choose whole, minimally refined foods (whole-wheat bread, brown rice, etc.), as magnesium is often lost during grain refining.

Why is diet not always enough?

Despite this apparent abundance, intakes are often insufficient. Several reasons explain this deficit:

• Depletion of agricultural soils (reduction in the mineral content of foods).
• Industrial diet poor in nutrients.
• Excessive cooking that destroys part of this mineral.
• Restrictive or unbalanced diets (poor in fruits, vegetables, legumes).
• Stressful and sedentary lifestyles.

It is in these contexts that a magnesium dietary supplement can be considered, particularly for athletes, to increase the intake of this nutrient.

Different forms of magnesium in dietary supplements

Magnesium bisglycinate

Magnesium bisglycinate is a chelated form, in which magnesium is bound to two glycine molecules (an amino acid). This structure significantly improves its bioavailability.

Magnesium citrate

Magnesium citrate is an organic form resulting from the combination of magnesium with citric acid.

Magnesium oxide

Magnesium oxide is an inorganic form composed of magnesium ions and oxygen. This form is slightly less bioavailable than other forms (citrate and bisglycinate).

How to choose your magnesium dietary supplement?

Given the diversity of products available on the market, it can be difficult to choose the right magnesium supplement. Here are the key steps to make an informed choice, adapted to your needs and respectful of your health.

Assess your personal needs

Start by determining if your lifestyle or physical condition justifies supplementation. Needs vary according to several factors:

• Age and sex,
• Level of physical activity (athletes, active, sedentary, etc.)
• Significant stress, unbalanced diet.

A preliminary assessment helps avoid poorly dosed supplementation.

Choose the appropriate form

Not all forms of magnesium are created equal. Prioritize those that offer good bioavailability and better digestive tolerance. For example:

• Bisglycinate or citrate are often better assimilated.
• Magnesium oxide may be suitable in some cases.

Also take into account any digestive sensitivities you may have.

Check product quality

A good dietary supplement relies on the quality of its formulation:

• Choose transparent brands with certifications.
• Look for products tested in laboratories for their purity, their exact magnesium content, and the absence of contaminants.
• Avoid supplements containing unnecessary excipients.

Seek advice from a healthcare professional

Before starting magnesium supplementation, it is strongly recommended to consult a qualified healthcare professional (doctor or nutritionist). This step is essential for:

- Adjusting the dosage to your specific needs, depending on your diet and lifestyle.

Magnesium supplementation is generally considered safe when used at recommended doses.

Magnesium dietary supplement: in summary

Magnesium is an essential mineral that contributes to many functions of the body. It is involved in numerous physiological functions: nervous system, muscle function, energy metabolism, normal bones, and much more.

While a balanced diet can cover daily needs, certain situations (significant stress, intensive sports practice, depleted diet) may justify the intake of magnesium dietary supplements.

Magnesium is not a miracle product, but when used correctly, it provides genuine support for the body.

Sources:

1. Tarsitano MG, Quinzi F, Folino K, Greco F, Oranges FP, Cerulli C, Emerenziani GP. Effects of magnesium supplementation on muscle soreness in different type of physical activities: a systematic review. Journal of Translational Medicine. 2024. doi: https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-024-05434-x
2. ANSES. Les références nutritionnelles en vitamines et minéraux. 2025. https://www.anses.fr/fr/content/les-references-nutritionnelles-en-vitamines-et-mineraux