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8 signs of magnesium deficiency

Written by John Davis

Last updated: September 15, 2022

Magnesium is a critical electrolyte necessary for normal cellular and organ function (1). It acts as a cofactor in over 300 enzymatic reactions. You may require magnesium for proper muscle and neural function, bone health, immune response, and blood sugar regulation (2,3). 

Hypomagnesemia, or simply low levels of magnesium in the bloodstream, is a growing concern for the American populace. If the levels fall below 1.46 mg/dL, a physician may diagnose you as having hypomagnesemia or low magnesium levels (4). 

Nearly half the adult population does not consume the recommended magnesium daily (5). However, falling short of the recommended dietary allowance(RDA) and having magnesium deficiency are two different things.

With only 1% of the magnesium in the body being present in the bloodstream, true magnesium deficiency isn’t commonplace. Research indicates only less than 2% of individuals suffer from magnesium deficiency (6). 

Low magnesium levels in the body can escalate other health conditions, including diabetes. H

8 warning signs of magnesium deficiency (hypomagnesemia)

1. Loss of Appetite, Vomiting, and Nausea

An early symptom of low levels of magnesium is vomiting and severe diarrhea. Magnesium’s role in neural transmission is critical in the relaxation and contraction of the smooth muscles in the gut (7). Low levels of magnesium can result in spasms that induce nausea and vomiting. 

Vomiting is a side effect of nausea and may lead to losing more electrolytes, including magnesium. This can worsen the condition, especially for celiac disease patients (8). 

Low magnesium levels may also lower your appetite. You may feel queasy, an after-effect of nausea. It may be difficult to enjoy any meals when your stomach is off. 

Hypomagnesemia can affect the proper functioning of the nerves that detect hunger signals. This can result in loss of appetite. 

2. Fatigue

Magnesium is a key co-factor in many cellular metabolism reactions. These processes are crucial in the conversion of nutrients into energy. Low magnesium can lead to fatigue, characterized by physical or mental weakness and exhaustion (9). 

While everyone feels exhausted from time to time, chronic fatigue can lower the quality of your life. Low magnesium levels are among the nutrition deficiencies that can cause persistent muscle weakness and fatigue. 

Research indicates hypomagnesemia can worsen muscle weakness in patients suffering from myasthenia gravis and SIDS (9). Low magnesium levels lead to lower muscle potassium levels, a condition identified as hypokalemia (10). 

However, it’s essential to note that fatigue is a non-specific sign. General body weakness is not an indicator of deficiency unless accompanied by other symptoms. 

3. Muscle Spasms and Cramps

Muscle cramps, tremors, and twitches are common indicators of low magnesium. In severe deficiency, hypomagnesemia can result in motor seizures or convulsions. 

Hypomagnesemia is responsible for secondary hypocalcemia, a condition characterized by low levels of calcium in the body (11). Magnesium is a critical cofactor in properly functioning parathyroid glands, which regulate calcium levels in the body (12). 

Secondary hypocalcemia can result in muscle twitching, tremors, and spasms. Keep in mind that muscle twitches may arise from other factors, such as stress or excessive caffeine. 

If your muscle tremors persist, you may need to visit a physician.

4. Heart Arrhythmia

Arrhythmia is simply an irregular heartbeat, either too fast or too slow (13). It may occur when electrical impulses in the heart malfunction. 

Arrhythmias can have no symptoms in some while posing serious symptoms to others. Possible symptoms include:

  • Pain the chest
  • Dizziness
  • Light-headedness
  • Shortness of breath
  • palpitations

Magnesium is a critical electrolyte in properly functioning potassium ion pumps in the heart muscle tissue (14). Low levels can result in the improper firing of the nerves in the cardiac tissues, resulting in irregular heartbeats. 

Research indicates hypokalemia, a condition attributed to low potassium levels, is closely tied to hypomagnesemia (15). Observational evidence shows that patients with arrhythmias and congestive heart failure typically have lower magnesium levels. 

Additionally, magnesium supplements in experimental models have improved patients’ heart functions after administration (16,17). 

5. Migraines

Medical literature indicates a close relationship between hypomagnesemia and mild and moderate headaches or migraines(18). Patients typically have low magnesium levels during migraine attacks. 

Scientists hypothesize that magnesium treatment effectively treats mild headaches and migraines(19). Small studies through double-blinded clinical trials using placebos showed the effectiveness of magnesium in treating patients complaining of migraines. 

The studies point to hypomagnesemia being an independent factor in migraine occurrence. However, you may need to be wary of a magnesium overdose before treating your headache with supplements (20). 

6. High Blood Pressure

Scientists believe low magnesium is closely tied to increased blood pressure, a key risk factor in heart disease (21). Low magnesium levels can increase intracellular calcium levels, which promote vasoconstriction. 

Magnesium also plays a critical role in nitric oxide formation (22). Nitric oxide is a natural vasodilator. Low magnesium can lower nitric oxide secretion, thus leading to vasoconstriction and increasing your blood pressure. 

However, human trials on BP-lowering through magnesium supplementation remain inconclusive. The benefits of magnesium-based treatments remain confined to controlled studies. 

More clinical studies may be necessary to fully understand the role of magnesium on hypertension and other cardiovascular diseases. 

7. Osteoporosis 

Osteoporosis is a condition identified through characteristic loss of bone mass, weakening the bones, and increasing the risk of fractures (23). This condition arising from an imbalance between bone deposition and resorption affects millions across the globe, with over 40 million in the US at risk. 

Magnesium deficiency can increase the risk of developing osteoporosis. Scientists believe magnesium plays a critical role in the crystal formation in bone cells (24). 60% of the total magnesium in the body is present in the bone. Deficiency can indirectly impact bone deposition leading to loss of bone mass. 

Additionally, magnesium is vital in the proper functioning of the parathyroid hormone. The hormone increases calcium levels when deficient. Secondary hypocalcemia from low magnesium levels can lead to bone resorption and osteoporosis (25).

8. Mood Disruptions

Research indicates that magnesium may be critical in regulating your mood and clinical manifestation of mental health conditions (26). 

Magnesium ions play a critical role in regulating the calcium flow in nerves. A deficiency may result in a malfunctioning neural network whose symptoms may function as depression. Scientists hypothesize that magnesium deficiency can lead to anxiety (27). However, conclusive evidence is still lacking. 

Lack of magnesium can lead to nerve disruption, affecting your mood. Apathy and delirium may be serious side effects of the deficiency. 

Causes of Magnesium Deficiency

Hypomagnesemia may arise from a variety of reasons, including:

  • Little or impaired intake
  • Excessive loss
  • Poor absorption 
  • Movement from extracellular fluid to other locations

Here’s a detailed outlook on some common causes of magnesium deficiency.

Too little Intake 

Nutritional deficits can arise from poor feeding, starvation, and severe illnesses (28). Malabsorption syndromes, including celiac disease and Crohn’s disease, can cause hypomagnesemia. 

Celiac disease is an autoimmune disorder that causes inflammation of the small intestine. Crohn’s disease is a condition that causes inflammation in the digestive tract. Both conditions can cause malabsorption of magnesium by interfering with its absorption from food or supplements.


Alcohol is a diuretic that leads to the loss of essential electrolytes from the body. Scientists indicate that alcoholics may lose up to 260% of their blood magnesium level through excretion via the kidneys (29). 

Diabetic ketoacidosis

Diabetes is a chronic disease that affects the way your body uses insulin. It’s usually caused by high blood sugar, which occurs when you don’t make or use enough insulin to manage your blood glucose levels properly.

Increased polyuria due to diabetes can lead to loss of magnesium through the urine (30). 

Prolonged Vomiting and Diarrhea

You may experience symptoms of hypomagnesemia if you are vomiting or have diarrhea, especially if it occurs in large amounts over a long period. The prolonged loss of electrolytes may eventually lower the magnesium levels within the body (31). 

As such, chronic laxative use can also increase your risk of magnesium deficiency. Laxative use can cause diarrhea, leading to magnesium loss in the body. 


Some medications can cause hypomagnesemia, including diuretics and antibiotics.


These drugs increase urine production by relaxing the muscles that control urination. They treat high blood pressure, heart failure, and other conditions. The increased amount of water in the body causes magnesium to be lost through the kidneys (32). 


Antibiotics kill bacteria in your body but also kill off good bacteria along with them—this may cause diarrhea that depletes magnesium levels even more quickly than usual.

Other drugs such as antihistamines, anti-inflammatories, steroids, or herbal supplements can also interfere with normal magnesium levels.

How to Get Enough Magnesium

The amount of magnesium that you require may vary. Age and sex assigned at birth may influence the magnesium required during different life stages. 

Foods Rich in Magnesium

Related: Foods high in magnesium

Magnesium is found naturally in many foods. However, it’s not always easy to get enough of it as the body only absorbs less than 30% of ingested magnesium (33).

Magnesium can be found in:

  • Leafy greens like spinach, kale, and Swiss chard
  • Nuts such as almonds and cashews
  • Seeds like pumpkin seeds or sunflower seeds
  • Whole grains such as brown rice
  • Beans such as black beans (34)

Supplements are another way that you can use to ensure you get the right amount of magnesium. However, you may need to talk to your physician to determine whether magnesium supplements are the right option. 

While it’s hard to have a magnesium overdose through food intake, supplements risk causing hypermagnesemia. This is a condition characterized by high levels of magnesium in the bloodstream. Too much magnesium can cause stomach cramps, diarrhea, and hypotension. 

Wrapping Up

While true magnesium deficiency is rare, hypomagnesemia can raise significant health concerns. Symptoms are typically subtle unless the levels go extremely low. 

The deficiency can be identified through fatigue, muscle spasms, high blood pressure, migraine, nausea, and irregular heartbeat. Most of these signs are nonspecific and may require a blood magnesium test to confirm the low magnesium levels. 

Luckily, you can source magnesium from various food sources. Alternatively, you can supplement your dietary intake with magnesium supplements. However, make a point to consult your physician to avoid hypermagnesemia.


John Davis