Magnesium can be found on mineral water bottles, food packaging, and in numerous dietary supplements. The mineral is particularly often associated with muscles, sports, energy, or relaxation. However, not every widespread statement is as straightforward as it first appears.
In this article, magnesium is explained simply: you will learn about the mineral's functions in the body, the daily requirement, and which foods are good sources. We also clarify when supplementation may be beneficial, what different magnesium compounds mean, and why muscle cramps do not automatically indicate a magnesium deficiency.
Briefly explained
Magnesium is an essential mineral that the body cannot produce itself. It is involved in normal muscle function, energy metabolism, nervous system function, protein synthesis, and the maintenance of normal bones, among other things.
For adults, the German Nutrition Society (Deutsche Gesellschaft für Ernährung) estimates a daily intake of 350 milligrams for men and 300 milligrams for women. Magnesium is found, for example, in whole-grain products, legumes, nuts, seeds, green vegetables, and magnesium-rich mineral water.
What is magnesium?
Magnesium is a mineral and belongs to the so-called bulk elements. These are minerals that are present in the body in comparatively larger quantities and must be regularly consumed through diet.
In the body, magnesium primarily exists as a positively charged magnesium ion. Approximately half to two-thirds of the body's magnesium is found in the bones. Another large portion is stored in muscles and other tissues. Only a very small amount circulates in the blood.
The body cannot produce magnesium itself. It must absorb it through food, beverages, or, if necessary, dietary supplements.
What are the functions of magnesium in the body?
Magnesium is involved in numerous biochemical reactions. It often acts as a so-called cofactor. This means that certain enzymes require magnesium to perform their functions.
Magnesium is involved in reactions in energy metabolism, protein synthesis, and the function of nerves and muscles, among other things.
Magnesium contributes to normal muscle function
Muscles work through a coordinated interplay of electrical signals and various minerals. Magnesium is involved in the processes by which muscle cells can contract and relax.
The approved statement is: "Magnesium contributes to normal muscle function."
This does not mean that additional magnesium automatically leads to stronger muscles, increases athletic performance, or prevents muscle cramps. The approved health claim describes a normal physiological function of the nutrient.
Magnesium contributes to normal energy metabolism
The term energy metabolism describes the biochemical processes by which the body generates and utilizes energy from nutrients.
Magnesium is involved in reactions where the central energy carrier ATP is processed. ATP stands for adenosine triphosphate and supplies many processes in the cells with energy.
However, magnesium itself does not provide calories and is not an energy source like carbohydrates, fat, or protein.
Magnesium contributes to the normal functioning of the nervous system
Nerve cells transmit information using electrical and chemical signals. Magnesium is involved in various processes required for this signal transmission.
The approved statement regarding the normal functioning of the nervous system does not mean that magnesium automatically eliminates stress, acts against anxiety, or has an immediate calming effect.
Magnesium contributes to normal protein synthesis
During protein synthesis, the body produces new proteins from amino acids. These proteins perform numerous tasks, for example, as components of muscles, enzymes, and tissues.
The fact that magnesium contributes to normal protein synthesis does not mean that additional intake automatically accelerates muscle growth. Muscle growth depends, among other things, on training, energy intake, protein intake, recovery, and overall health.
Magnesium contributes to the maintenance of normal bones and teeth
A large portion of the body's magnesium is found in the bones. There, the mineral is a component of the bone structure and involved in bone metabolism processes.
In addition to magnesium, other factors play a role, including calcium, vitamin D, protein intake, physical activity, and hormonal influences.
Magnesium contributes to electrolyte balance
Magnesium itself is an electrolyte. Electrolytes are minerals that are electrically charged in body fluids.
Electrolyte balance describes the regulated distribution of various charged particles inside and outside the body cells. These include sodium, potassium, chloride, calcium, and magnesium.
Magnesium contributes to the reduction of tiredness and fatigue
Magnesium also has the approved health claim: "Magnesium contributes to the reduction of tiredness and fatigue."
This does not mean that magnesium eliminates all forms of fatigue. Sleep deprivation, stress, infections, medication, and numerous other factors can influence fatigue.
How much magnesium do you need per day?
The German Nutrition Society uses so-called estimated values for magnesium for an adequate intake.
| Person Group | Estimated daily value |
|---|---|
| Men from 19 years | 350 mg magnesium |
| Women from 19 years | 300 mg magnesium |
| Pregnant women | 300 mg magnesium |
| Breastfeeding women | 300 mg magnesium |
The values refer to the total daily intake from food and beverages. They are not a recommendation to take the same amount as a dietary supplement every day.
Why are these estimated values?
The exact individual magnesium requirement cannot be clearly determined for every person. Therefore, the DGE derives an adequate intake from scientific data on absorption and supply.
An estimated value is a guide for healthy population groups. It does not represent a personal dosage instruction.
Do physically active people need more magnesium?
Physical activity can change energy consumption, food intake, and, in certain situations, mineral losses. Magnesium is also excreted in small amounts through sweat.
However, this does not mean that a universally applicable additional magnesium dose can be derived for all athletes. The actual requirement depends on, among other things, diet, training volume, sweat loss, body size, and individual supply.
Studies on magnesium supplementation in sports have yielded different results. A general increase in performance through magnesium has therefore not been proven.
Which foods contain a lot of magnesium?
Magnesium is found in both plant-based and animal-based foods. Plant-based foods such as seeds, nuts, legumes, and whole-grain products are usually particularly rich.
Typical magnesium sources include pumpkin seeds, sunflower seeds, almonds, cashews, rolled oats, whole-wheat bread, brown rice, lentils, beans, chickpeas, green leafy vegetables, cocoa, and magnesium-rich mineral water.
The actual content can vary depending on the variety, cultivation, processing, and preparation.
Magnesium-rich foods compared
| Food | Typical serving size | Classification |
|---|---|---|
| Pumpkin seeds | 30 g | very rich in magnesium |
| Almonds | 30 g | good source |
| Rolled oats | 70 g | good everyday source |
| Whole-wheat bread | 2 slices | provides a contribution |
| Lentils, cooked | 200 g | also provides protein and fiber |
| Spinach, cooked | 200 g | plant-based magnesium source |
| Mineral water | 1 liter | depending on the declared magnesium content |
Why are whole grain products good sources of magnesium?
A large proportion of the minerals in a grain are found in the outer layers and the germ. In highly milled white flour, many of these components are removed.
Whole grain products therefore generally contain more magnesium than comparable products made from refined flour.
Can mineral water provide magnesium?
Yes. However, the magnesium content of mineral water differs significantly between various sources.
On the label, you will usually find the content in milligrams per liter. Mineral water with 100 milligrams of magnesium per liter provides 100 milligrams of magnesium per liter.
Mineral water can thus contribute to intake but does not replace a varied diet.
How does the body absorb magnesium?
Absorption primarily occurs in the small intestine. Some can also be absorbed in the large intestine.
The percentage of what the body absorbs from food depends, among other things, on the amount consumed and the supply status. With lower intake, the body can absorb proportionally more. With a very high single dose, the percentage of absorption often decreases.
The kidneys play an important role in regulation. With low intake, they can retain more magnesium. With high intake, more is excreted in the urine.
What does bioavailability mean?
Bioavailability describes the proportion of an ingested substance that actually enters the body and is generally available there.
For magnesium, it is influenced by, among other things, the magnesium compound, the amount ingested, solubility, meal composition, digestion, individual supply status, and concurrently taken substances or medications.
A high percentage of absorption does not automatically mean that a product is better for everyone. The actual amount of magnesium, tolerability, price, and purpose of intake are also crucial.
Magnesium from food or supplements?
Food provides magnesium along with other nutrients, fiber, and energy. For healthy people, a varied diet should therefore fundamentally form the basis of supply.
Dietary supplements provide magnesium in a concentrated form. They can be practical in certain situations but are not automatically necessary.
Supplementation can be professionally reviewed, for example, in cases of proven insufficient supply, consistently very unbalanced nutrition, certain diseases, certain medications, or increased losses under special conditions.
Whether supplementation is useful cannot be assessed solely on the basis of non-specific symptoms.
What magnesium compounds are there?
In dietary supplements, magnesium is bound to different compounds. Magnesium citrate, magnesium bisglycinate, magnesium oxide, magnesium carbonate, magnesium malate, magnesium chloride, and magnesium lactate are commonly used.
The compound influences, among other things, the proportion of elemental magnesium, how well the product dissolves, and how it is individually tolerated.
What is elemental magnesium?
Elemental magnesium refers to the actual amount of the mineral magnesium – regardless of the compound it is bound to.
For example, a product may contain 1,000 milligrams of magnesium citrate without providing 1,000 milligrams of pure magnesium. Only a portion of the weight is accounted for by the actual magnesium.
Therefore, for comparing different products, the indication "magnesium" or "of which magnesium" is crucial, not just the total weight of the compound.
Is magnesium citrate better than magnesium oxide?
This cannot be answered so generally. Organic compounds like magnesium citrate are often more soluble than magnesium oxide. Magnesium oxide, however, contains a high proportion of elemental magnesium, but is sometimes less well tolerated in higher amounts.
Studies on the absorption of different compounds vary in methodology and results. A single ranking that applies to all people and applications cannot be reliably derived from this.
What is magnesium bisglycinate?
In magnesium bisglycinate, magnesium is bound to the amino acid glycine. This compound is often advertised with good tolerability.
Statements such as "magnesium bisglycinate improves sleep," "calms the nervous system," or "is more potent than other forms" should not be derived solely from the contained amino acid.
When should you take magnesium?
For healthy people, there is no general time of day when magnesium must be taken.
More important are the actual magnesium content, tolerability, regular intake, possible interactions, and total magnesium intake.
Those who react to a larger single dose with digestive issues may tolerate smaller portions or taking it with a meal better.
Magnesium in the morning or evening?
Magnesium can generally be taken in the morning or evening. The timing of intake alone does not determine whether the magnesium is absorbed or effective.
Many people take magnesium in the evening because it fits their routine. However, this does not mean that taking it in the evening automatically improves sleep in healthy individuals.
Do you lose magnesium when sweating?
Sweat contains small amounts of magnesium, in addition to water, sodium, and chloride. However, the most significant electrolyte loss by quantity during sweating usually concerns sodium and chloride.
Therefore, heavy sweating does not automatically mean that only or primarily magnesium needs to be replaced. How relevant individual losses become depends on sweat rate, duration of exertion, diet, and environmental conditions.
Does magnesium help with muscle cramps?
Muscle cramps can have many causes and influencing factors. These include physical fatigue, unaccustomed exertion, neuromuscular factors, diseases, and certain medications.
A magnesium deficiency can impair muscle and nerve function. However, this does not mean that every muscle cramp is caused by a magnesium deficiency.
Studies show no general reliable benefit of magnesium supplementation for preventing ordinary muscle cramps. For exercise-induced muscle cramps, the data is limited.
What does magnesium deficiency mean?
A medical magnesium deficiency refers to insufficient magnesium supply or an abnormal magnesium status. It should not be diagnosed based solely on individual non-specific symptoms.
Possible symptoms can have many different causes. These include, for example, fatigue, muscle symptoms, or general weakness. These symptoms do not prove a magnesium deficiency.
In case of persistent or severe symptoms, medical clarification is advisable.
Can you take too much magnesium?
Magnesium from normal foods generally causes no problems in healthy individuals. The kidneys can largely excrete excess magnesium.
However, higher amounts from dietary supplements or medications can cause digestive problems. These primarily include soft stools, diarrhea, abdominal discomfort, and nausea.
In cases of severely impaired kidney function, excretion may be compromised. High-dose intake should only occur after medical consultation in such cases.
Can magnesium interact with medications?
Magnesium can affect the absorption of certain medications. For example, some antibiotics, osteoporosis medications, and other drugs may be relevant.
A time interval may be necessary between taking magnesium and certain medications. Those who take medication regularly should clarify the combination with a pharmacy or doctor's office.
Common Mistakes and Misunderstandings
"Magnesium is only important for muscles"
Magnesium is not only involved in muscle function. It also plays a role in energy metabolism, the nervous system, electrolyte balance, protein synthesis, and the maintenance of normal bones.
"Every muscle cramp means magnesium deficiency"
Muscle cramps can have various causes. A specific mineral deficiency cannot be inferred from a cramp.
"The more magnesium, the better"
A higher intake does not automatically lead to greater benefits. High single doses can worsen tolerability and cause diarrhea.
"The number on the front always shows the pure magnesium amount"
The amount of the magnesium compound is not the same as the amount of elemental magnesium. For comparison, the declared actual amount of magnesium is crucial.
"Organic magnesium forms are always superior"
The compound can influence absorption and tolerability. Nevertheless, no single form can be generally described as the best solution for all individuals.
"Magnesium automatically makes you tired"
Magnesium is not a sleep aid or sedative. Normal nervous system function is not to be equated with a sedative effect.
How to practically classify your magnesium intake
Before choosing a dietary supplement, you can review your diet for a few days based on the following questions:
- Do you regularly eat whole grain products?
- Do legumes appear several times a week?
- Do you eat nuts or seeds?
- Does your mineral water contain significant amounts of magnesium?
- Do you have any illnesses or are you taking medication?
- Is it about general supply or treating symptoms?
For many people, it is more sensible to first plan regular magnesium-rich foods rather than directly treating individual symptoms with a supplement.
Magnesium simply explained: The most important points summarized
Magnesium is an essential mineral involved in numerous normal bodily functions. These include muscle function, the nervous system, energy metabolism, protein synthesis, electrolyte balance, and the maintenance of normal bones.
The DGE specifies an estimated value of 350 milligrams daily for adult men and 300 milligrams for adult women. Good sources include whole grain products, legumes, nuts, seeds, green vegetables, and magnesium-rich mineral water.
Dietary supplements can be useful in certain situations but are not automatically necessary. Muscle cramps, fatigue, or poor sleep do not prove magnesium deficiency. The overall diet, actual intake, individual circumstances, and, if necessary, professional clarification are decisive.
Frequently Asked Questions
What is magnesium simply explained?
Magnesium is an essential mineral. The body needs it, among other things, for the normal function of muscles and the nervous system, energy metabolism, protein synthesis, and the maintenance of normal bones.
How much magnesium do you need daily?
The DGE specifies an estimated value of 350 milligrams for adult men and 300 milligrams of magnesium per day for adult women. The values refer to the total intake from food and beverages.
Which foods are particularly rich in magnesium?
Good sources include pumpkin seeds, sunflower seeds, almonds, legumes, oats, whole grain bread, green vegetables, and magnesium-rich mineral water.
Do athletes need more magnesium?
Sport can affect magnesium balance, but there is no general additional dose for all athletes. Diet, training volume, sweat loss, and individual supply status are decisive.
Does magnesium help against muscle cramps?
Not every muscle cramp is due to magnesium deficiency. Studies show no general reliable benefit of magnesium supplementation for preventing common muscle cramps.
Is magnesium citrate better than magnesium oxide?
Magnesium citrate is usually more soluble, while magnesium oxide contains a higher proportion of elemental magnesium. Which form is useful depends on the amount, tolerability, and personal situation.
Can you take magnesium every day?
Magnesium can generally be taken daily through food. For dietary supplements, dosage, total intake, tolerability, kidney function, and possible interactions should be considered.
Should you take magnesium in the morning or in the evening?
For healthy people, there is no universally ideal time. Magnesium can be taken in the morning or evening. Regularity and tolerability are usually more important than the exact timing.
Sources
- German Nutrition Society: Magnesium – Reference values for nutrient intake.
- German Nutrition Society: Selected questions and answers about magnesium.
- European Food Safety Authority: Dietary Reference Values for Magnesium and Phosphorus, 2015.
- EFSA Panel on Dietetic Products, Nutrition and Allergies: Scientific Opinion on health claims related to magnesium. EFSA Journal, 2010; 8(10):1807. DOI: 10.2903/j.efsa.2010.1807.
- National Institutes of Health, Office of Dietary Supplements: Magnesium – Fact Sheet for Health Professionals.
- Garrison, S. R. et al.: Magnesium for skeletal muscle cramps. Cochrane Database of Systematic Reviews, 2020.
- Miller, K. C. et al.: An Evidence-Based Review of Exercise-Associated Muscle Cramps. Journal of Athletic Training, 2022.