Understanding magnesium deficiency: Signs, causes and solutions

Low magnesium can cause muscle cramps, fatigue, poor sleep as well as heart problems, yet many overlook the signs

When we think of essential nutrients, calcium for bones or iron for blood usually comes to mind. But there’s another mineral quietly keeping our heart rhythm steady, our muscles working smoothly, and our nerves firing properly – magnesium. Sadly, many people don’t even realise when their magnesium levels drop too low.

 

In today’s fast-paced world, stress, processed food, and lifestyle habits often nudge us towards deficiencies we may overlook. Magnesium deficiency, also known as hypomagnesaemia, is one such silent health concern.

 

How common is magnesium deficiency? 

Magnesium plays a vital role in over 300 biochemical processes, including muscle and nerve function, blood sugar regulation, and heart rhythm stability, shared Dr Mukesh Batra, founder and chairman emeritus, Dr Batra’s Healthcare. Magnesium deficiency primarily affects the nervous system, muscles (including those in the heart), and bones.

 

 

“Around the world, between two and 15 per cent of the general population likely have low magnesium levels. In India, following changing diets and the growing use of processed foods, studies suggest up to one in three adults could have less than ideal magnesium levels,” shared Dr Amrita Bhattacharyya, respiratory critical care specialist at The Calcutta Medical Research Institute (CMRI).

“In intensive care units, more than 40 to 50 per cent of patients may be affected by hypomagnesaemia,” she said.

 

Early warning signs of deficiency 

Very mild deficiency of magnesium may not have symptoms at all, explains Dr Vaibhav Kesarkar, consultant physician for nephrology & kidney transplant, Fortis Hospital, Mumbai.

 

The physical symptoms of low magnesium levels are

• Loss of appetite
• Nausea
• Fatigue
• Weakness
• Numbness and tingling
• Cramps

 

“There may be certain mental symptoms also, subtle mood changes, irritability, anxiety, memory issues, personality changes, neuropsychiatric symptoms,” adds Dr Kesarkar.

 

Long-term effects of deficiency 

Long-term or severe deficiency may cause:

• Cardiac arrhythmias and increased cardiovascular risk, especially in heart failure patients.
• Persistent muscle weakness and cramps.
• Secondary hypocalcaemia and hypokalaemia (because magnesium is required for potassium and calcium homeostasis).
• Possible links to osteoporosis and poor glycaemic control over time. In critical care, low magnesium worsens outcomes.

 

Causes of magnesium deficiency 

• Inadequate dietary intake - low consumption of nuts, seeds, green leafy vegetables, and whole grains.
• People suffering from celiac disease, chronic diarrhoea or short bowel are at risk.
• Increased renal loss — most commonly due to loop/thiazide diuretics, some antibiotics, and prolonged hyperglycemia (blood glucose level is abnormally high, most commonly associated with diabetes).
• Proton-pump inhibitors (PPIs) have been linked to low magnesium with long-term use.
• Excess alcohol, high caffeine intake, and critical illness (ICU patients) are also at increased risk.

 

Can food help restore balance? 

Preventing magnesium deficiency begins with diet. Leafy greens, nuts, seeds, whole grains, and legumes are excellent sources, says Dr Batra.

 

Food: Spinach, Swiss chard, pumpkin & sunflower seeds, almonds, cashews, whole grains, legumes, avocados, bananas, and dark chocolate - supply magnesium along with fibre and micronutrients.

 

Supplements: Oral magnesium salts (oxide, citrate, glycinate) can be used when diet alone is insufficient. Elemental magnesium 200–400 mg per day is a common therapeutic range but should be individualized. Magnesium citrate/ glycinate tends to be better absorbed and gentler on the gut than magnesium oxide.

 

Severe deficiency (example: arrhythmia, seizures, very low serum Mg) requires IV magnesium sulfate administered in a hospital.  “Excessive supplementation in patients with renal impairment can cause dangerous hypermagnesemia (nausea, hypotension, respiratory depression). Always follow your physician's advice for high doses,” cautioned Dr Bhattacharyya.

 

When to consult a doctor? 

If you experience recurrent muscle cramps, unexplained palpitations, persistent weakness, or neuropsychiatric changes. “Be more careful if you take diuretics, have GI losses, are an alcoholic, or are critically ill. Also check magnesium if you have hypokalemia (low potassium) and hypocalcaemia (low calcium) that is difficult to correct,” explains Dr Bhattacharyya. 

 

Why is diagnosis tricky? 

Diagnosis is tricky because most body magnesium is intracellular or in bone. “Serum magnesium — the most commonly ordered test — may be normal even when total body stores are low. Other tools like red-cell magnesium, 24-hour urinary magnesium, or magnesium loading tests are more informative but less widely available. Clinical suspicion, symptoms, and medical history (medications, diarrhoea, diuretics) are critical to prompt testing and treatment,” shared Dr Bhattacharyya.

 

“Artificial intelligence (AI) is proving to be revolutionary in this area, surpassing conventional diagnostics by identifying subtle biomarker variations, mapping comorbidities, and examining medication history to reveal hidden risks at a much earlier stage. AI guarantees that magnesium is no longer a mineral that is overlooked but rather a recognized component, by transforming dispersed health data into actionable insights,” said Sid Das, co-founder of eGenome.ai, a firm working in predictive health technologies.   

 

Prevention: What experts recommend 

The best way to stay on top of magnesium levels is through diet and lifestyle awareness.

 

Daily needs: Adult recommended dietary intake (RDI) ranges roughly from 310 to 420 mg/day (women ≈310–320 mg; men ≈400–420 mg). Aim to meet the requirements from food first. 

Dietary advice: Increase nuts, seeds, green leafy vegetables, legumes, whole grains and moderate intake of dairy and fish. Limit excessive alcohol and high-caffeine drinks. 

Drug interactions: If you are on diuretics, certain antibiotics, or long-term PPIs, discuss magnesium monitoring with your physician.

   

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This report is for informational purposes only and is not a substitute for professional medical advice.