All you need to know about Magnesium

by | Sep 30, 2020 | Dietetic Coaching, Micronutrients, Nutrition, Nutrition basics, NUTRITIONAL GUIDE, Uncategorized | 0 comments

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Magnesium is one of the minerals most present in the body. Among its many roles, magnesium is involved in more than 300 enzymatic reactions. But what do we need in magnesium? When should we consume it? Foodvisor explains everything you need to know about magnesium.

What is magnesium?

Magnesium is an essential mineral for the human body. The human body contains 25mg of magnesium. 50 to 60% of this amount is stored in the bones and 25% in the muscles. The rest is stored in the liver, kidneys, blood, and heart. Thus, it is the fourth most abundant cation (ion with a positive charge) in the body, after calcium and phosphorus for example.

To be effective, magnesium must be combined with different vitamins and minerals: calcium, sodium, potassium and vitamin B6.

What are the effects of magnesium on the body?

The roles of magnesium are numerous since this mineral is involved in 300 enzymatic reactions. To begin with, magnesium plays an important role in the proper functioning of the nervous system: it actively participates in the transmission of nerve impulses and modulates the reactivity to stress in order to fight against it.

Next, magnesium is necessary for the formation of bones and teeth in combination with phosphorus. It also contributes to the fixation of calcium on the bones.

Also, magnesium plays a role in energy production: it is involved in glucose metabolism, as well as in the synthesis of proteins and lipids. Magnesium is necessary for the cell because it allows the cell to use glucose by increasing the sensitivity of insulin. As a reminder, insulin is the hormone that allows glucose to pass from the blood to the cells and this action is increased by the presence of magnesium.

Magnesium is also essential for muscle contraction and helps maintain a steady heart rate.

Finally, magnesium stimulates the immune system because it increases phagocytosis and antibody formation. Phagocytosis is a cellular defense process consisting of destroying a foreign body. In this way, magnesium plays an anti-allergic and anti-inflammatory role.

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What are the symptoms of magnesium deficiency?

Consumption of excess magnesium can cause diarrhea and sometimes nervous disorders. However, the majority of cases show on the contrary a magnesium deficiency. This magnesium deficiency is often due to insufficient intakes in the general population. Otherwise, a magnesium deficiency can be observed in case of an unbalanced diet, alcohol abuse, taking medication, intestinal imbalance, or in times of stress.

The consequences of a magnesium deficiency on the body are numerous: anxiety, stress, constipation, heart palpitations, neuromuscular irritability, kidney, vascular and liver problems.

What are our magnesium needs?

Our magnesium needs are important because a large part is rejected by the body in the urine. The daily magnesium requirement is 420mg for a man, 360mg for a woman, 6mg per kilo of body weight for a sportsman.

Needs are increased in cases of anxiety, chronic stress or overwork. Some populations have a higher need:

  • Athletes,
  • The elderly,
  • Pregnant women,
  • Hyperactives,
  • Alcoholics,
  • People with intestinal absorption problems (celiac or Crohn’s disease for example),
  • People on a diet.

What foods are the richest in magnesium?

The foods richest in magnesium are:

  • Dried seaweed (sea lettuce, sea bean, kombu, aonori, wakame)
  • Rice bran
  • Seeds of pumpkin, flax, sunflower, sesame, poppy, chia
  • Wheat bran
  • Unsweetened cocoa powder
  • Brazil nuts, almonds
  • Spices and dried aromatic herbs

Nevertheless, these foods are generally eaten in small quantities. So, there are other food sources of magnesium: whole grains, legumes (lentils, white beans, peas, chickpeas), shellfish, leafy vegetables.

For seeds and cereals, it is important to soak them well before eating them to eliminate all anti-nutritional agents such as phytates for example. They prevent the absorption of nutrients and are not essential to the body.

When to have magnesium?

As we have seen, there are certain cases in which it is important to take care to meet magnesium requirements. But there are also certain situations in which it can be interesting to supplement one’s diet with magnesium: in stressful periods such as exams, a complicated period at work or the holidays.

In fact, there is a vicious circle between stress and magnesium: too much stress causes a magnesium deficiency and magnesium deficiency causes an increase in sensitivity to stress. From a physiological point of view, stress decreases the body’s magnesium by accelerating its loss in the urine.

Periods of fatigue are also conducive to dietary magnesium supplementation.

It is important to know that magnesium must not be taken in combination with calcium-rich meals (green vegetables, oilseeds, meat, dairy products, …) because calcium prevents its absorption in the stomach. You should also avoid taking magnesium at the same time as other medications or coffee.

Does magnesium help you sleep?


It is often said that magnesium helps with sleep. This is because a good intake of magnesium reduces anxiety and stress, which makes falling asleep and sleeping less disturbed. Magnesium should therefore not be considered a sleeping pill.

Also, magnesium has a role in the production of melatonin, the so-called sleep hormone. This is what makes for a good night’s sleep.

Does magnesium make you lose weight?


In the same way that magnesium improves sleep, it contributes to weight loss because it helps reduce stress. Indeed, stress is known to release cortisol, a hormone that increases hunger and therefore leads to an increase in food intake and sometimes snacking.

In addition, magnesium is involved in the mechanism of weight loss because it allows the body to use carbohydrates and lipids.

You now know all about magnesium, all you have to do now is to bring it to your plates or through adapted and expertly chosen food supplements. Don’t hesitate to ask for advice from a dietician, doctor or pharmacist.

Article written by Romane, dietician at Foodvisor.


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