Signs you may be low in magnesium: Symptoms, causes & what to do
Magnesium might not get as much attention as some other nutrients, but this essential mineral is involved in hundreds of processes throughout the body. From normal muscle and nerve function to energy production and electrolyte balance, magnesium quietly works behind the scenes every day.
Yet many of us don't give much thought to how much magnesium we're actually getting — until our body starts giving us clues that something may be out of balance.
So, what does magnesium actually do, what can contribute to low magnesium levels, and what are some of the signs worth paying attention to?
Let's take a closer look.
What does magnesium do in the body?
Magnesium is an essential mineral, meaning our bodies need it but can't produce it themselves. We therefore need to obtain magnesium through our diet and, when appropriate, supplementation.
Magnesium contributes to many important functions, including:
Normal muscle and nerve function
Energy production and metabolism
Maintaining healthy bones
Electrolyte balance
Normal psychological function
Protein synthesis
Normal heart function
This is why magnesium isn't simply a "sleep mineral" or something we reach for when we have a muscle cramp. It plays a role across many different systems in the body.
What are the signs of low magnesium?
Low magnesium can present differently from person to person, and many of the symptoms associated with magnesium deficiency can also have numerous other causes.
Some signs that may occur with inadequate magnesium include:
Muscle cramps, twitches or spasms
Magnesium is involved in normal muscle contraction and relaxation. Muscle cramps, twitching or spasms can sometimes occur when magnesium levels are low, although hydration, activity levels and other electrolyte imbalances can also contribute.
Fatigue or low energy
Magnesium plays an important role in cellular energy production. When magnesium intake is inadequate, fatigue and weakness can occur.
Of course, tiredness can have many causes — from poor sleep and stress to iron deficiency, thyroid issues and inadequate nutrition — so persistent fatigue is worth discussing with your healthcare practitioner.
Changes in sleep
Magnesium is involved in normal nervous-system function, which is one reason it has become so closely associated with relaxation and sleep.
That doesn't mean every sleep problem is caused by low magnesium, but adequate magnesium intake is one piece of the much larger sleep puzzle.
Headaches
Magnesium has been studied in relation to headaches and migraine, and some people who experience migraines have been found to have lower magnesium levels.
Frequent or severe headaches should always be properly investigated rather than simply assumed to be nutritional.
Tingling or numbness
More significant magnesium deficiency can affect nerve and muscle function and may contribute to sensations such as tingling, numbness or abnormal muscle contractions.
These symptoms can have many causes, however, so they should be discussed with a healthcare professional.
Changes in mood
Magnesium is involved in normal neurological and psychological function. Researchers continue to investigate the relationship between magnesium status, stress and mood.
Rather than thinking of magnesium as a treatment for stress or mood concerns, it is more helpful to think of it as one of the many nutrients our nervous system requires to function normally.
What can cause low magnesium?
Not getting enough magnesium-rich food is one possible reason, but magnesium status isn't determined by diet alone.
Factors that may contribute to low magnesium include:
A diet low in magnesium-rich whole foods
Certain gastrointestinal conditions that affect absorption
Ongoing diarrhoea or digestive problems
Some medications
Excessive alcohol consumption
Certain medical conditions
Increased losses through the kidneys
Poor overall nutrient intake
This is an important distinction: sometimes the question isn't simply "Am I consuming enough?" but also "Is my body absorbing and retaining what I'm consuming?"
Which foods contain magnesium?
Food should generally be our first source of essential nutrients.
Magnesium can be found naturally in foods including:
Nuts and seeds
Legumes
Whole grains
Leafy green vegetables
Avocado
Some fish
Dark chocolate and cacao
Pumpkin seeds, chia seeds, almonds and spinach are particularly useful sources.
Including a variety of whole foods in your diet also provides magnesium alongside fibre, protein, healthy fats and many other vitamins and minerals.
How much magnesium do we need?
Magnesium requirements vary according to age, sex and life stage.
Australian nutrient reference values recommend roughly 310–320 mg per day for most adult women and 400–420 mg per day for most adult men, with requirements changing during pregnancy, breastfeeding and different stages of life.
Rather than becoming overly focused on hitting an exact number every day, aim for a varied, nutrient-dense diet that regularly includes magnesium-rich foods.
How do you know if your magnesium is actually low?
Symptoms alone can't tell you whether you have a magnesium deficiency.
If you are experiencing persistent symptoms that could be related to magnesium, speak with your GP or preferred healthcare practitioner. They can consider your symptoms, diet, medications and medical history and determine whether testing is appropriate.
This is particularly important because symptoms such as fatigue, weakness, cramps and heart palpitations can have many causes that deserve proper investigation.
What about magnesium supplements?
For some people, supplementation can be a convenient way to increase magnesium intake when dietary intake isn't meeting their needs.
But if you've ever walked into a health store and looked at the magnesium section, you'll know there are a lot of options.
Magnesium citrate, glycinate, oxide and chloride are just a few examples, and different formulations can vary in elemental magnesium content, tolerability and how they're used.
You'll also find magnesium as tablets, powders, capsules and liquids.
At Alchemist's Cabinet, we use magnesium chloride in our Liquid Magnesium, with a 10 mL serve providing 290 mg of elemental magnesium.
Its naturally strong mineral taste means we recommend diluting it in water or another drink if preferred.
Supplementation isn't a replacement for a varied diet, and more isn't always better. If you're unsure whether magnesium supplementation is appropriate for you — particularly if you have a medical condition, take medications, are pregnant or breastfeeding — speak with your healthcare practitioner.
The bigger picture: minerals work together
One of the things we talk about often at Alchemist's Cabinet is looking at nutrition as a whole rather than focusing on one nutrient in isolation.
Magnesium doesn't work alone.
Our bodies rely on a complex balance of minerals, vitamins, protein, fats, carbohydrates and other nutrients to carry out everyday functions. Hydration, sleep, stress, gut health and overall diet can all influence how we feel as well.
So if you've recognised several symptoms on this list, resist the temptation to immediately assume "I must be magnesium deficient."
Instead, consider it an invitation to look at the bigger picture.
Are you eating a varied diet?
Are you regularly including mineral-rich foods?
How is your sleep?
How is your digestion?
Are you taking medications that can affect nutrient levels?
Could another nutrient be involved?
And are persistent symptoms worth discussing with your healthcare practitioner?
Sometimes these simple questions can tell us much more than focusing on a single symptom.
The takeaway
Magnesium is an essential mineral involved in muscle and nerve function, energy production, bone health and many other processes throughout the body.
While symptoms such as muscle cramps, fatigue, twitching and weakness can sometimes occur when magnesium is low, they aren't specific to magnesium deficiency and shouldn't be used to self-diagnose.
Start with a varied diet rich in whole foods, pay attention to what your body is telling you, and seek professional advice when symptoms persist.
And if dietary intake isn't meeting your needs, a magnesium supplement may be one option to discuss with your preferred healthcare practitioner.
