Feeling tired, experiencing muscle cramps, or struggling to get a good night’s sleep? These problems can have many causes, but sometimes, low magnesium levels may play a role.
Magnesium is an essential mineral that supports muscle and nerve function, energy production, and a normal heart rhythm.
Because early deficiency can be difficult to recognize, knowing the possible warning signs can help you understand when to seek medical advice.
Here are 10 possible signs and symptoms of magnesium deficiency, along with what else might be causing them.
1. Loss of Appetite
A reduced appetite can be an early sign of magnesium deficiency. You may feel less interested in food or find yourself eating less than usual.
Interestingly, a case-control study involving 108 women found a link between magnesium levels and leptin, a hormone that helps regulate appetite. Women with obesity had higher leptin levels, lower magnesium levels in their blood and red blood cells, and greater magnesium loss through urine.
The findings show an association, not proof that changes in leptin cause magnesium deficiency or appetite loss.
2. Nausea and Vomiting
Nausea and vomiting can be other early signs of magnesium deficiency.
In one case report, a 15-year-old boy with severe magnesium deficiency experienced abdominal pain, nausea, and vomiting during exercise. His symptoms improved after receiving magnesium treatment.
Even so, the exact link between magnesium deficiency and digestive symptoms remains unclear.
3. Fatigue and Muscle Weakness
Feeling unusually tired, even after getting enough sleep, or experiencing muscle weakness may be a symptom of magnesium deficiency.
Your body needs magnesium for energy production and normal muscle and nerve function. When magnesium levels become significantly low, you may experience fatigue, weakness, and other symptoms.
One study found that 20 patients with chronic fatigue syndrome had lower red blood cell magnesium levels than 20 healthy controls. In a related trial, 12 of 15 patients who received magnesium injections reported improvements in energy, mood, and pain, compared with 3 of 17 who received a placebo.
Keep in mind that fatigue and muscle weakness can have many causes, including poor sleep, iron or vitamin D deficiency, thyroid problems, and other health conditions. These symptoms alone do not confirm that your magnesium levels are low.
4. Muscle Cramps and Spasms
Muscle cramps, twitches, and spasms are commonly associated with magnesium deficiency, particularly when the deficiency becomes more severe.
Magnesium helps regulate nerve signaling, muscle contraction and maintain the balance of electrolytes, including calcium and potassium. When magnesium levels become too low, this balance can be disrupted, potentially causing excessive muscle contractions that lead to cramps and spasms.
However, research suggests that taking magnesium supplements does not necessarily relieve ordinary muscle cramps. A Cochrane review of 11 trials involving 735 participants found that magnesium supplements were unlikely to meaningfully reduce these cramps in older adults.
5. Numbness and Tingling
As magnesium deficiency worsens, some people may experience numbness or tingling, often described as pins and needles in the hands, feet, or other parts of the body.
Magnesium helps regulate nerve signaling and muscle function. Severe magnesium deficiency can also contribute to low calcium levels, which may cause tingling and numbness by increasing nerve excitability.
These sensations can also result from other conditions, including diabetes, nerve compression, and vitamin B12 deficiency. If numbness or tingling persists, seek medical advice to identify the underlying cause.
6. Sleep Problems
Struggling to fall asleep, waking up frequently during the night, or feeling unrefreshed in the morning can have several causes. Magnesium supports normal nerve function and may play a role in processes involved in sleep regulation.
A 2024 study of more than 20,000 adults found a link between a magnesium depletion score and certain sleep problems, including sleep apnea. However, it found no significant association with insomnia or insufficient sleep.
Similarly, a review of nine studies involving 7,582 adults found that observational research linked magnesium status with sleep quality, but clinical trials of magnesium supplements showed inconsistent results.
Overall, more research is needed to understand how magnesium levels may affect sleep.
7. Changes in Mood or Personality
Severe magnesium deficiency can sometimes cause changes in personality or mental functioning as it worsens. These changes may include confusion or difficulty thinking clearly.
A review of 60 reported cases linked severe magnesium deficiency to neurological problems, including tremors, poor coordination, slurred speech, and muscle jerks. Some patients had lasting symptoms, highlighting the importance of early diagnosis and treatment.
8. Abnormal Heart Rhythm
Magnesium helps maintain normal electrical activity in the heart. When magnesium levels become significantly low, the heart’s rhythm may become irregular.
A 20-year study of 3,530 adults found that those with the lowest magnesium levels were about 50% more likely to develop atrial fibrillation, a type of irregular heartbeat, compared with those with higher levels. The findings suggest an association, but further research is needed to confirm a causal link.
Severe magnesium deficiency can also lower potassium and calcium levels, further disrupting normal heart function.
An irregular heartbeat can have many causes and does not necessarily indicate magnesium deficiency. Seek urgent medical care if you experience palpitations accompanied by chest pain, fainting, severe dizziness, or shortness of breath.
9. Seizures
Seizures are an uncommon but serious symptom of severe magnesium deficiency. Very low magnesium levels can disrupt normal brain activity and trigger seizures. Magnesium deficiency may also occur alongside other electrolyte imbalances, such as low calcium, which can further increase the risk of seizures.
A case series describing three patients found that magnesium deficiency contributed to their seizures. The seizures improved or stopped after magnesium levels were corrected, highlighting the importance of early diagnosis and treatment.
A seizure requires immediate medical attention, especially if it is a person’s first seizure, lasts longer than five minutes, or occurs repeatedly without recovery between episodes. Call emergency services if this happens.
What Causes Magnesium Deficiency?
Magnesium deficiency is uncommon in otherwise healthy people solely because of low dietary intake. The kidneys normally help conserve magnesium when intake decreases. However, certain conditions and circumstances can increase the risk.
Common causes and risk factors include:
- Digestive conditions
- Long-term heavy alcohol use
- Kidney conditions
- Excessive urination
- Hyperaldosteronism
- Prolonged diarrhea
- Severe burns
- Pancreatitis
- Excessive sweating
- Inadequate food intake or malnutrition
- Certain medications, including diuretics, proton pump inhibitors, and some antibiotics
If you have one or more of these risk factors and experience persistent symptoms, talk to a healthcare professional about whether magnesium testing is appropriate.
How Can You Improve Your Magnesium Intake?
If your magnesium intake is low, including more magnesium-rich foods in your diet can help you meet your nutritional needs.
Good food sources include:
- Pumpkin seeds
- Almonds and cashews
- Spinach
- Beans and lentils
- Whole grains
- Soy foods
- Dark chocolate
Try to include a variety of these foods regularly rather than relying on a single food or supplement.
If a healthcare professional confirms magnesium deficiency, treatment may involve oral magnesium supplements or, in more serious cases, magnesium given intravenously. The appropriate treatment depends on the severity of the deficiency, its cause, and your kidney function.
Avoid taking high-dose magnesium supplements without medical guidance. Supplements can cause diarrhea and interact with certain medications, and excessive magnesium can be dangerous for people with impaired kidney function.
When Should You See a Doctor?
Occasional fatigue or muscle cramps do not necessarily indicate magnesium deficiency. However, persistent symptoms deserve attention, especially if you have a digestive disorder, diabetes, a history of heavy alcohol use, or take medication that can lower magnesium levels.
Seek urgent medical care for seizures, fainting, severe confusion, or a potentially serious abnormal heartbeat.
Getting the right diagnosis matters because these symptoms may have causes other than magnesium deficiency, and treatment should address the underlying problem.
The Bottom Line
Magnesium deficiency can cause symptoms ranging from fatigue and muscle cramps to seizures and abnormal heart rhythms in severe cases. However, these symptoms can have many causes and do not confirm a deficiency.
Eating magnesium-rich foods, such as nuts, seeds, legumes, leafy greens, and whole grains, can help meet your needs.
If symptoms persist or you have risk factors for deficiency, consult a healthcare professional.