7 Signs of Magnesium Deficiency

 

You might be eating reasonably well, sleeping enough hours, and still feel like something's off. Low energy. Twitchy muscles. A mind that won't quieten down at night.

The culprit is often something most people never think to check: magnesium.

Around 60% of the UK population fails to meet recommended magnesium intake levels. Not dramatically deficient but quietly under-fuelled. And because magnesium deficiency frequently manifests as nonspecific symptoms like irritability, muscular spasms, weakness and exhaustion, most people simply put it down to stress, a bad week, or getting older.

Here are 7 signs worth paying attention to.

1. Muscle Cramps and Twitches

This is one of the most recognisable signs. Up to 60% of adults experience leg cramps on a regular basis and because of magnesium's role in neuromuscular signals and muscle contraction, researchers have observed that magnesium deficiency is often to blame.

Beyond leg cramps, slight eyelid twitching or cramps and tension in the jaw muscles are also relatively common signs of low magnesium.

If you're waking up at 3am with a calf cramp or finding your eyelid flickering for days at a time, your magnesium levels are worth looking at.

2. Persistent Tiredness and Low Energy

Feeling exhausted even after a full night's sleep is one of the most frustrating experiences  and one of the most commonly linked to low magnesium. Low energy, weakness and fatigue are common symptoms of magnesium deficiency.

The reason is straightforward: magnesium is essential for energy production at a cellular level. Whether it's your nervous system, energy metabolism, muscle function or immune system  magnesium is involved in over 600 enzymatic reactions and biological processes. When levels drop, every system in your body has to work harder.

3. Poor Sleep Quality

Struggling to fall asleep, waking during the night, or never feeling truly rested? Evidence shows that magnesium can help with insomnia symptoms such as poor sleep quality, waking early in the morning and difficulty falling asleep. As a result of better sleep quality, adequate magnesium is also associated with lower odds of feeling exhausted during the day.

This is one of the most searched magnesium benefits in the UK  and for good reason. It's also one of the clearest feedback loops: poor sleep depletes magnesium further, and low magnesium makes sleep worse.

4. Feeling Tense or On Edge

Magnesium plays an inhibitory role in the normal stress response and neurotransmission. Studies show that individuals experiencing psychological stress have a decreased magnesium status  and that stress may increase magnesium loss, while magnesium deficiency may increase the body's vulnerability to stress, creating a difficult cycle.

If you notice you're more irritable than usual, harder to calm down, or feel wound up without obvious cause, low magnesium may be playing a role.

5. Irregular Heartbeat or Palpitations

This is one of the less commonly known signs but worth being aware of. An irregular heartbeat  which might feel like skipped beats or palpitations — can be a sign of magnesium deficiency, and may have a knock-on effect causing dizziness or shortness of breath.

Cardiac arrhythmia is one of the recognised signs of low magnesium, particularly in more pronounced deficiency. If you experience palpitations regularly, always speak to your GP first but it's worth mentioning your diet and magnesium intake when you do.

6. Numbness or Tingling

Some individuals with low magnesium experience numbness or tingling in the extremities. This happens because magnesium is essential for healthy nerve function. When levels fall, nerve signalling can become disrupted, leading to that pins-and-needles sensation often in the hands, feet, or face.

It's an easy symptom to dismiss or attribute to sitting awkwardly, but if it's happening regularly without obvious cause, it's worth noting.

7. Digestive Issues

Nausea, vomiting and loss of appetite are all early symptoms you might experience if you don't get enough magnesium. These are easy to attribute to something else — a stomach bug, stress, or something you ate which is exactly why low magnesium goes undetected for so long.

If digestive complaints are recurring and no other cause has been identified, it's a reasonable step to look at your magnesium intake alongside other factors.

Why Is Magnesium Deficiency So Common in the UK?

It's not just about diet. Key drivers of low magnesium in the UK include soil depletion, ultra-processed diets, increased stress levels, and higher physical activity without corresponding dietary adjustments.

The loss of magnesium during food refining and processing is significant white flour loses around 82%, polished rice 83%, and white sugar 99% of its magnesium content. The modern British diet, heavy in processed foods, quietly strips out one of the most important minerals your body needs.

The NHS recommends 300mg of magnesium daily for adult men and 270mg for adult women. Most people aren't close.

What to Do If You Recognise These Signs

Start with food. Magnesium-rich sources include pumpkin seeds, almonds, spinach, dark chocolate, legumes, and whole grains. Minimally processed, whole foods are always the best source.

If you're consistently falling short through diet alone, a supplement in a well-absorbed form can help fill the gap. Magnesium bisglycinate is one of the gentler, more bioavailable forms easier on digestion than cheaper oxide forms, and better absorbed by the body.

If you suspect a deficiency, speak to your GP. A serum magnesium blood test is the standard first step in UK clinical practice.