Magnesium Deficiency – Common Signs and What the Research Says
Common signs associated with low magnesium are tiredness, muscle cramps, muscle twitches and a feeling of restlessness. Pronounced magnesium deficiency is uncommon in otherwise healthy people, because the kidneys regulate magnesium levels carefully – but a low intake over time is more common, particularly with a monotonous diet, high alcohol consumption or certain medications. Confirmed deficiency is investigated and treated by a healthcare provider.
Below we go through the signs, who is at risk and how to top up magnesium safely.
What is magnesium deficiency?
Magnesium deficiency (hypomagnesaemia) means that the body's magnesium level is lower than normal. Magnesium is needed in over 300 enzymatic processes, including nerve and muscle function, energy metabolism and normal protein synthesis. Since the body only stores limited amounts – mostly in the skeleton and muscles – a steady intake through the diet is important.
There is a difference between actual deficiency and a suboptimal intake. Actual deficiency is relatively uncommon in healthy people, while an intake below the recommendation is considerably more common. According to the Swedish Food Agency, the recommended daily intake for adults is around 280–350 mg.
Common signs and symptoms associated with low magnesium
The signs are non-specific, which means they can have many other causes. So it is not possible to "diagnose" magnesium deficiency on your own based on symptoms. Among the most commonly mentioned are:
Muscles and nerves
- Muscle cramps and muscle twitches (e.g. in the calves, often at night)
- Tingling or numbness in the hands and feet
- Muscle weakness
Energy, sleep and mood
- Tiredness and low energy
- Restlessness and difficulty winding down
- Difficulty sleeping
- Low mood, worry and irritability
- Difficulty concentrating
Other signs
- Headache
- Reduced appetite and nausea
- Palpitations or a feeling of irregular heart rhythm
- Constipation
Because magnesium contributes to the reduction of tiredness and fatigue, to normal muscle function, normal functioning of the nervous system, normal psychological function and normal electrolyte balance (approved EFSA claims), it is logical that tiredness, muscle and mood symptoms are the ones mentioned most often. But the same symptoms could just as easily be due to lack of sleep, stress, iron deficiency or something else – which is why an assessment by a healthcare provider is the only way to confirm deficiency. The list above should be seen as examples, not as a checklist for self-diagnosis.
Who is at risk?
| Group | Why the risk is higher |
|---|---|
| High alcohol consumption | Increases magnesium loss via the urine |
| Certain gastrointestinal diseases | Impaired absorption in the gut (e.g. Crohn's disease, coeliac disease) |
| Type 2 diabetes | Increased excretion via the kidneys |
| Certain medications | E.g. proton pump inhibitors and some diuretics |
| Monotonous diet | Low intake of green vegetables, nuts and wholegrains |
| Older adults | Often lower food intake and poorer absorption in the gut |
| Pregnancy and breastfeeding | Increased need during a period of life |
| Hard exercise and heavy sweating | Can increase losses with large fluid losses |
Belonging to a risk group does not mean you have a deficiency – but it does make it extra worthwhile to eat magnesium-rich foods and to raise any symptoms with a healthcare provider.
How do I know if I have magnesium deficiency?
You cannot determine it yourself based on symptoms, because the signs are non-specific and overlap with many other conditions. The reliable way is an assessment by a healthcare provider, which may include a blood test (serum magnesium).
It is worth knowing that only a small part of the body's magnesium is found in the blood – most is stored in the skeleton and muscles. A standard blood test therefore does not always capture the whole picture. That is why a healthcare provider makes an overall assessment of your symptoms, diet, any medications and other illnesses before drawing conclusions. Contact a healthcare provider if you have persistent problems or belong to a risk group, rather than guessing on your own.
How to top up magnesium – diet first
The best source of magnesium is food. Plenty of magnesium is found in:
- Green leafy vegetables (spinach, chard)
- Nuts and seeds (almonds, cashews, pumpkin seeds)
- Wholegrains (oats, wholemeal bread) and legumes (beans, lentils)
- Oily fish (mackerel, salmon)
- Avocado and banana
- Dark chocolate
A varied diet with these foods normally covers the requirement for most healthy people. According to the Swedish Food Agency, pronounced deficiency is uncommon when the diet is well balanced.
If the diet is not enough, a supplement can top up. Organic forms such as glycinate and citrate are well absorbed; glycinate is especially gentle on the stomach. If you want to choose the right form, we have a guide on magnesium glycinate vs citrate vs malate, or you can go straight to magnesium glycinate.
When should you seek care?
Contact a healthcare provider if you have pronounced or persistent symptoms such as muscle cramps, palpitations or numbness, or if you have an illness or medication that increases the risk of deficiency. Confirmed magnesium deficiency should be investigated and treated by a doctor – supplementing on your own does not replace a medical assessment.
Frequently asked questions (FAQ)
The only reliable way is a blood test via a healthcare provider, because the symptoms are non-specific and can be due to many other things. Tiredness and muscle cramps are often associated with low magnesium, but can just as easily have other causes.
Can magnesium deficiency cause muscle cramps?Muscle cramps and twitches are among the symptoms most often associated with low magnesium, because the mineral contributes to normal muscle function. Cramps can, however, also be due to dehydration, hard exercise or other factors.
How much magnesium do I need per day?The Swedish Food Agency states around 280–350 mg per day for adults, with some variation by sex and age. A large part normally comes from the diet.
Can you get too much magnesium?Magnesium from food is not associated with risk for healthy people, because the kidneys get rid of any excess. High doses from supplements can, however, cause loose stools. Stick to the dosage on the packaging.
Which form of magnesium is best with a low intake?Organic forms such as glycinate and citrate are well absorbed. Glycinate is gentle on the stomach and suits daily use, while citrate is affordable and well documented.
Can magnesium deficiency affect sleep?Difficulty sleeping and difficulty winding down are sometimes associated with low magnesium, because the mineral contributes to normal functioning of the nervous system and normal psychological function. Sleep problems, however, often have other causes, such as stress or irregular habits.
Can magnesium deficiency cause palpitations?A feeling of irregular heart rhythm is mentioned among the signs associated with low magnesium. Palpitations should, however, always be assessed by a healthcare provider, especially if they are recurring or pronounced.
Does a blood test show whether I have magnesium deficiency?A blood test (serum magnesium) can be part of a healthcare provider's assessment, but since only a small part of the body's magnesium is in the blood, it does not always capture the whole picture. The provider therefore also weighs in symptoms, diet and other factors.
Can stress and coffee affect magnesium levels?Prolonged stress and high consumption of alcohol can increase the need or the losses. A steady diet with magnesium-rich foods helps keep the intake stable.
What time of day is best to take magnesium?There is no fixed rule – choose a time you will remember, preferably with a meal for a comfortable stomach. Always follow the dosage on the packaging.
Summary
Low magnesium is most often associated with tiredness and muscle symptoms, but the symptoms are non-specific and are confirmed by a healthcare provider. Top up primarily through the diet and, if needed, supplement with a well-absorbed form. See our range or read about choosing the right form of magnesium.
The content is general information, not medical advice. For persistent or pronounced symptoms, contact a healthcare provider. Supplements are not a substitute for a varied diet.
