❖ The amount of magnesium to be ingested per day varies according to age and sex. In stressful situations, during competitive sports and during pregnancy and lactation, the need for magnesium may be increased.

❖ An overdose of magnesium is generally not possible in a healthy person, but in certain circumstances, it can lead to side effects such as diarrhea, vomiting, dizziness or fatigue.


❖ Magnesium preparations must be taken over the long term (4 to 6 weeks) to replenish the magnesium reserves. The time of intake does not affect absorption.

❖ Interactions with magnesium can occur with certain drugs, zinc, iron, phosphates and diets rich in lipids and proteins.

Our body cannot produce its own magnesium stores by itself. We have to supply it with this essential mineral in sufficient quantity through a complete and varied diet or supplement it with magnesium preparations. The body of an adult contains about 25 grams of magnesium, about 95% of which is stored in bone, muscle and nerve cells.

In this article you will find the daily need for magnesium necessary for different groups of people , the possible side effects in case of overdose and the points to take into account when taking magnesium.

The daily need for Magnesium

The National Agency for Food, Environment and Work Health Security (ANSES) has defined recommended nutritional intake (ANC) according to the sex and period of people’s lives.

For an adult, the recommended magnesium intake is set at 6 mg / kg / day . Thus, for a woman of approximately 60 kg, the ANC will be 360 ​​mg / day and for a man of approximately 70 kg, the ANC will be 420 mg / day. For children, the recommended nutritional intake depends on age and not on gender. We have grouped all the data in a table for you.

Daily magnesium requirement in adults

For an adult, the recommended magnesium intake is set at 6 mg / kg / day . Thus, for a woman of approximately 60 kg, the ANC will be 360 ​​mg / day and for a man of approximately 70 kg, the ANC will be 420 mg / day. For children, the recommended nutritional intake depends on age and not on gender.

In France, to give you an idea, in view of the different recommended nutritional intakes and the amounts of magnesium brought in on average via food, the health authorities have fixed at 300mg the maximum daily dose of magnesium that can be provided by a food supplement. .

These are of course estimated values, since the actual need of an individual depends on various factors and can be increased in certain life situations.

Among the factors that lead to an increase in magnesium requirements, we can cite:

  • -Pregnancy and breast feeding
  • -Competitive sports and physical exercises
  • -Chronic stress
  • -Diseases (for example from the gastrointestinal tract)
  • -Consumption of drugs
  • -Chronic alcohol consumption

Daily need for magnesium in children and adolescents

The recommended intake for babies, who receive all the necessary nutrients after birth via breast milk, is 24 to 60 milligrams of magnesium per day. Industrially produced infant formulas also contain a sufficient amount of magnesium. For infants , an intake of 80 milligrams of magnesium per day is recommended. Thereafter, an intake of 6.0 milligrams per kilogram of body weight per day is advised. Adolescents therefore have a higher need in relation to their body weight because the body needs a higher magnesium intake during the growth phases. According to the ANSES, children aged 4 to 13(depending on age and gender) should take 130 to 280 milligrams of magnesium per day. The teenagers from 13 years (age and sex) have a daily need of 370 to 410 milligrams of magnesium.

Daily need for magnesium in pregnant and lactating women

The ANSES recommendations also indicate the amount of magnesium to be ingested during pregnancy and breastfeeding.  During pregnancy, these needs increase to provide the infant with everything it needs to develop. Even a small magnesium deficiency can disrupt the course of pregnancy. Thus, it is recommended that the expectant mother consume, in the third trimester, 400 mg of magnesium per day, instead of the usual 360 mg.

In addition, it is advisable to be particularly attentive at the beginning of pregnancy , even if the needs are not yet increased because the nausea sometimes accompanying the first trimester can cause vomiting which worsen the deficits in minerals.

To exclude the risk of magnesium deficiency, pregnant and breastfeeding women should consult their doctor and only take magnesium supplements after consulting them. During a medical consultation, it is also possible to discuss the duration of taking magnesium during pregnancy and the appropriate dosage. As a general rule, it is a good method to take the recommended daily dose spread over the day to avoid possible side effects.

Daily magnesium requirement in athletes


Athletes should also achieve the recommended daily magnesium intake with their normal diet. However, the magnesium requirements may be higher, depending on the extent and intensity of the sport . Since magnesium contributes to normal energy metabolism and muscle function, people who play sports (especially endurance and competition athletes) need more magnesium and must ensure an adequate intake of magnesium.

In addition, due to increased sweating during strenuous physical activity, athletes lose more essential minerals such as calcium or magnesium. The daily needs of athletes must nevertheless be determined individually , since the sport can be practiced at different intensities and the amount of perspiration depends on the people. Magnesium intake can therefore also vary from one sport to another.

Daily magnesium requirement during a period of stress

When the human body is under stress , it releases increased amounts of hormones such as adrenaline or cortisol, which in turn increase the excretion of magnesium by various metabolic pathways. Thus, the need for magnesium in stressful situations is increased.

Magnesium requirement – Table

ANSES recommendations concerning magnesium intake (mg / day), by age and sex:

Age Man Women

1 to 3 years



4 to 6 years old



7 to 9 years old



10 to 12 years old



13 to 19 years old







In general, the regular intake of magnesium in sufficient quantity through the diet is much more effective than a significant punctual intake of magnesium . A balanced and varied diet provides us with all the necessary nutrients that our body needs.

If your magnesium level in the blood is too low, you can improve your eating habits and eat foods that are richer in magnesium. On the other hand, in the event of clinically proven deficiency, your doctor may recommend the additional intake of preparations based on magnesium. However, there are a few things to consider when dosing.

The German Federal Institute for Risk Assessment (BfR) recommends taking a maximum of 250 milligrams of magnesium per day in the form of food supplements (preferably in two portions spread over the day), as too high a dose of magnesium may have a laxative effect on the body. For magnesium supplementation, an intake of 200 to 400 milligrams per day is sufficient. If magnesium does not cause side effects and there are no risk factors for overdose, higher therapeutic doses are also possible on the recommendation of your doctor.

In addition, there are no scientifically proven recommendations on the amount of magnesium to take in case of migraines or muscle cramps, nor on the appropriate magnesium dosage for athletes.


Magnesium preparations available on the market often contain doses higher than the maximum recommended amount and therefore exceed actual daily needs. If too much magnesium has been absorbed, an overdose of magnesium is generally not possible in a healthy person, because our body eliminates excess magnesium by the kidneys. However, in patients with kidney disease, too much magnesium can be harmful. This is why people with limited kidney function should consult a doctor before taking magnesium supplementation.

Side effects

An overdose of magnesium can in some people lead to side effects symptoms such as diarrhea, vomiting, dizziness or even severe fatigue . If undesirable side effects caused by magnesium occur, the dose may be reduced or the preparation may be temporarily interrupted.




As most preparations are highly dosed with magnesium, the manufacturers recommend taking it twice in the form of tablets or capsules. In any case, remember that neither magnesium nor other preparations are suitable for self-medication and you should definitely consult a doctor before taking magnesium.

What else should I think of when I take it?

  1. Period of use
  2. Setting time
  3. Interaction with other nutrients or drugs

Magnesium – How long does supplementation last?

Magnesium preparations must be taken over the long term (at least 4 to 6 weeks), since an occasional intake is not enough to remedy a magnesium deficiency and to replenish the magnesium reserves of organsime. It may take some time before a noticeable effect of supplementation is felt in the body. The first signs of an improved magnesium supply can only be seen after about four weeks . In order to build a sufficient supply of magnesium, athletes who are preparing for a competition, for example, may start taking it a few weeks earlier.

Magnesium supplement – when to take it

As with many other dietary supplements, the question arises as to whether magnesium should be taken in the morning or in the evening. For magnesium, the timing is not important . However, as the level of magnesium in the blood generally drops slightly during the night or early in the morning, taking magnesium is particularly suitable in the evening before going to sleep. It is also recommended to take it in the evening if magnesium intake is used to treat nighttime muscle cramps. If you want to take your daily dose of magnesium throughout the day, you can take one capsule in the morning and one in the evening before going to bed. In addition, magnesium in high dosesis often better tolerated if taken with a meal. The question of whether magnesium should be taken before or after sports is not so easy to resolve. In general, athletes should ensure a regular intake of magnesium. Taking this medication before or during exercise can cause unwanted side effects. Therefore, the best time to take magnesium supplementation would be after sports.


There are various assumptions about the interaction of magnesium with other nutrients. For example, the minerals zinc and iron, phosphates, oxalates and phytates, as well as a diet rich in lipids and proteins inhibits the absorption of magnesium. Various drugs such as antibiotics, laxatives or diuretics can reduce the blood level of magnesium. It is therefore advisable to take magnesium supplements, preferably at least two hours before or after taking medication. It is also not recommended to take magnesium and zinc at the same time, as a high intake of zinc can inhibit the absorption of magnesium.to avoid possible interactions between these two minerals. Excessive intake of caffeine can increase the excretion of magnesium in the urine when magnesium and coffee are taken at the same time.

Calcium-magnesium ratio

Magnesium is a calcium antagonist and opposes calcium overload in cells. According to this principle, magnesium regulates the absorption of calcium in cells. For a perfect interaction of calcium and magnesium, an adequate supply of these two minerals is crucial. According to scientists, the ratio of calcium to magnesium in the diet should be around 2: 1 . Due to the antagonistic effects of the latter two, it has long been assumed that the combined intake of magnesium and calcium leads to a reduction in magnesium intake. As the absorption of magnesium and calcium from the intestine takes place through different transport routes, magnesium and calcium supplements at the recommended doses can be taken at the same time.

In what form to take Magnesium? 

Magnesium is now available on the market in many forms and can therefore be consumed in many different ways.

The most common forms of magnesium:

  • The tablets and capsules are the most popular dosage form, are easy to take and can be determined individually.
  • The effervescent tablets   are dissolved in a glass of water and have the advantage that the magnesium dissolved in water can be better absorbed by the body.
  • The direct pellets  are especially useful when traveling, as they can be taken without water and fit in any purse.
  • The drink granules also have the advantage that the magnesium dissolved in the water is better absorbed by the body.


Please enter your comment!
Please enter your name here