Magnesium deficiency: the 10 telltale signs (and how to remedy it)

Persistent fatigue, nighttime cramps, mounting stress, twitching eyelids... These everyday signs often have a common denominator: magnesium deficiency. In France, 70% of the population has insufficient intake, according to ANSES. Yet this mineral is involved in more than 300 enzymatic reactions in the body. Here’s how to recognize a deficiency and, above all, how to remedy it effectively.

Why are we so often deficient in magnesium?

Depleted agricultural soils: intensive farming practices have reduced the magnesium content of plant-based foods by 20 to 30% over the past 50 years. Chronic stress: cortisol secretion promotes the urinary excretion of magnesium. Food processing: refining grains removes up to 80% of the magnesium from the whole grain.

The 10 signs of magnesium deficiency

1. Persistent fatigue despite getting enough sleep

Magnesium contributes to the production of ATP, the cell’s energy molecule. A deficiency causes profound fatigue that does not disappear after a good night’s sleep.

2. Muscle cramps, especially at night

Magnesium regulates muscle contraction and relaxation. In cases of deficiency, muscles contract more easily - hence nighttime cramps in the calves or feet.

3. Twitching eyelids

These small involuntary tremors (fasciculations) are often the first visible sign of magnesium deficiency.

4. Nervousness, irritability, and anxiety

Magnesium regulates GABA, an inhibitory neuromodulator that promotes relaxation. A deficiency causes hyperexcitability: nervousness, impatience, and underlying anxiety.

5. Sleep problems

Difficulty falling asleep, nighttime awakenings, unrefreshing sleep... Magnesium is involved in melatonin synthesis and the regulation of the autonomic nervous system.

6. Headaches and migraines

Studies show that people who suffer from migraines often have lower magnesium levels. This mineral regulates vascular tension and neuronal excitability.

7. Constipation or slow bowel movements

Magnesium stimulates intestinal motility. A deficiency slows down bowel movements.

8. Heart palpitations

Magnesium regulates the ion channels of the heart muscle. Palpitations may be linked to a deficiency.

9. Cold extremities

Magnesium deficiency may contribute to a persistent feeling of cold in the hands and feet by disrupting vascular regulation.

10. Difficult recovery after exercise

Athletes lose magnesium through sweat. A deficiency slows protein synthesis and prolongs post-exercise muscle soreness.

Which form of magnesium should you choose?

Magnesium bisglycinate is the most recommended form: excellent absorption, very good digestive tolerance, and non-laxative. Magnesium oxide (the most common form) is absorbed at less than 4% - avoid it. The recommended daily intake is 375 mg for an adult.

The best dietary sources

Pumpkin seeds (270–350 mg/100g), almonds (150–270 mg/100g), legumes (60–90 mg/100g), dark chocolate 70%+ (150–170 mg/100g), and leafy green vegetables. Reaching 375 mg per day through diet alone remains difficult during periods of stress or sustained physical activity.

What to remember

Magnesium deficiency is one of the most widespread and underdiagnosed deficiencies in France. If you check several boxes on this list, consider taking magnesium bisglycinate supplements for 8 to 12 weeks. The effects on sleep, stress, and muscle recovery are often noticeable within the first few weeks.

Food supplements. If you are taking medication or have kidney disease, consult your doctor before taking any supplements.