Many of us are familiar with the better-known nutrients we need to stay healthy, including iron, vitamin C, and omega-3.

But one key mineral that’s often overlooked is magnesium. So what exactly is magnesium? Why is it so important? And how can we make sure that we’re getting enough?

Here’s everything you need to know about magnesium…

What is magnesium?

Magnesium is an essential mineral which is necessary for many of the body’s most important functions. It was named after the part of Greece where it was first discovered – Magnesia.

Magnesium is known for being the eighth-most abundant chemical element in the earth’s crust, and the fourth-most abundant within the human body.

Although magnesium wasn’t recognised as a chemical element until 1755, people were aware of its health benefits much earlier.

In 1618, a farmer from Epsom found that the water from a local saline spring helped to heal wounds, cuts, and rashes – and later, people discovered that this salty, bitter water was actually magnesium sulphate. Centuries later, ‘Epsom salt’ is still used to soothe and relax painful muscles.

Despite its importance (and the fact that it’s readily available in many different foods), many of us aren’t getting enough magnesium. Plus, when compared to other minerals like iron and zinc, magnesium is often overlooked – even though we need to eat much less of these minerals than we do magnesium.

What does magnesium do?

Magnesium has many important functions within the body. It helps us to maintain healthy heart rhythms, muscle and nerve functions, and to control glucose levels – and it can also act as a natural muscle relaxant.

Because it helps turn vitamin D into calcium, magnesium is needed for maintaining strong bones and for producing energy and protein.

Let’s take a closer look at some of magnesium’s most important functions…

1. Magnesium can improve bone health

When it comes to bone health, calcium is usually the mineral that people focus on, but research shows that magnesium is also crucial for maintaining healthy bones.

Studies have linked magnesium to higher bone density, better bone crystal formation, and a reduced risk of osteoporosis in older women.

You can read more about this in our article; How to improve bone health.

2. Magnesium can offer benefits against diabetes

Magnesium has also been shown to reduce the risk of type 2 diabetes.

This study found that most people with type 2 diabetes have low levels of magnesium in their system.

Because magnesium plays a key role in glucose control and insulin metabolism, it can also help people to better manage their diabetes.

3. Magnesium can improve cardiovascular health

There’s plenty of evidence to suggest that magnesium plays a key role when it comes to heart health.

This scientific review found that being deficient in magnesium can increase a person’s risk of developing cardiovascular problems – and people who take magnesium after suffering from a heart attack have been shown to have lower long-term risks.

Other research also suggests that not getting enough magnesium is linked to problems associated with cardiovascular health, like high blood pressure, dyslipidemia, atherosclerosis, arrhythmias (abnormal heart rhythms), and coronary artery disease. For example, doctors sometimes use magnesium during treatment for heart failure to reduce the risk of arrhythmia.

4. Magnesium can boost mood

Research suggests that getting enough magnesium may improve mood disorders like depression and anxiety. There’s also evidence that it can help with other psychological issues like agitation, irritability, and confusion.

Some scientists believe that the low magnesium content in many modern foods is partly responsible for the increased prevalence of depression, anxiety, and other psychological disorders.

While more research is needed, this study found that among depressed older adults, taking magnesium each day improved their mood as effectively as antidepressant medication did.

5. Magnesium can improve sleep

More recent studies have found that there may be a link between magnesium and sleep. To fall asleep, both your body and brain need to relax – and magnesium has been shown to activate the neurotransmitters that are responsible for calming the body and mind.

Studies on mice show that optimal levels of magnesium are key for normal sleep to occur, which suggests that not having enough magnesium in your system may lead to restless sleep, and even insomnia.

Plus, not only can magnesium help you fall asleep, but it can also increase the likelihood of your sleep being deep and restful. In one study, older adults who took magnesium supplements compared to a placebo group had a better quality of sleep. They also displayed enhanced levels of renin and melatonin, which are hormones that help to regulate sleep.

For more tips on how to improve your sleep, you might want to check out the sleep and fatigue section of our site.

6. Magnesium can improve migraines

Because magnesium deficiency can affect neurotransmitters and restrict blood vessel constriction (factors that are linked to migraines) some doctors and scientists believe that people who suffer from migraines are more likely to be deficient in magnesium.

This review found that taking 600mg of magnesium appeared to be a safe and effective way to prevent migraines. The American Migraine Foundation has also stated that people often use magnesium supplementation for migraine prevention.

7. Magnesium can improve performance

Magnesium can also play an essential role in exercise performance and recovery, and studies show that you need 10–20% more magnesium when you’re exercising compared to when you’re resting.

Because magnesium helps send blood sugar to your muscles and remove lactic acid (which can form during exercise and cause tiredness and painful muscles), it’s also important in recovering from more strenuous exercise, and protecting your muscles from damage.

What can happen if you don't get enough magnesium?

While serious magnesium deficiency is rare in the UK, it’s common for people to not get as much magnesium as they might need.

A study of 8,000 Brits found that around 70% of participants had low magnesium levels – and the Government’s National Diet and Nutrition Survey found that most children and teenagers also weren’t getting the recommended levels.

A person can become magnesium deficient for three reasons: they’re not getting enough magnesium from their diet, they’re not absorbing enough, or they’re excreting too much from their kidneys. Older adults are more at risk of magnesium deficiency because they generally don’t absorb as much magnesium – and also excrete more of it.

Alcoholics and heavy drinkers, people with type 2 diabetes or increased insulin resistance, and people with coeliac and Crohn’s disease are also more likely to suffer from magnesium deficiency. This is because their existing health conditions can make absorption more difficult, as well as excretion more likely.

Because magnesium plays such an important role in so many different bodily functions, the symptoms of deficiency can be varied. They can include tiredness and fatigue, insomnia, mood swings, muscle cramps, weakness and dizziness, headaches, irritability of the nervous system, and an irregular heartbeat.

How to make sure you're getting enough magnesium

According to the UK government, the recommended daily allowance of magnesium for adults is 300mg a day for men and 270mg for women. Yet, because those over the age of 55 tend to find magnesium more difficult to absorb, older adults may sometimes require more. You should always talk to your doctor if you think you might be deficient in magnesium.

The easiest and best way to make sure you’re getting enough magnesium is to make some dietary changes – and the good news is that magnesium is present in lots of common, healthy foods.

Generally speaking, people who want to get more magnesium through their diet should incorporate more high-fibre foods like cereal and whole grains, as well as dark leafy greens.

Some of the foods that are highest in magnesium include…

  • Pumpkin seeds – 46% of the RDI in a quarter cup (16g)
  • Spinach (boiled) – 39% of the RDI in a cup (180g)
  • Swiss chard (boiled) – 38% of the RDI in a cup (175g)
  • Dark chocolate (70–85% cocoa) – 33% of the RDI in 3.5 ounces (100g)
  • Black beans – 30% of the RDI in a cup (172g)
  • Quinoa (cooked) – 33% of the RDI in a cup (185g)
  • Almonds – 25% of the RDI in a quarter cup (24g)
  • Cashews – 25% of the RDI in a quarter cup (30g)
  • Mackerel – 19% of the RDI in 3.5 ounces (100g)
  • Avocado – 15% of the RDI in one medium avocado (200g)
  • Soya milk – 15% of the RDI in a cup (175g)

Because nutrients work better when combined with other nutrients, where possible it’s always best to obtain vitamins and minerals through your diet rather than through supplements.

But, if you’re concerned that you may have low magnesium levels, or you suffer from any health conditions that might reduce your ability to absorb magnesium (or increase the likelihood of you excreting it), then you might want to talk to your doctor about taking a supplement.

Forms of supplementation include magnesium oxide, magnesium citrate, magnesium glycinate, magnesium orotate, magnesium carbonate, and magnesium lactate.

While magnesium oxide is found in many of the most popular supplements on the market, it’s also the hardest for the body to absorb. Magnesium lactate is twice as easy for our bodies to absorb as magnesium oxide, which means that you need to take less to achieve the same results.

However, be sure to speak to a health practitioner before deciding to take magnesium supplements as different supplements work best for different people. 

It’s worth noting that taking high levels of magnesium supplements (more than 350mg daily) can also be harmful. This is because it can build up in the body and cause side effects such as irregular heartbeat, low blood pressure, slowed breathing, and confusion. So if you do take a magnesium supplement, it’s important to follow government guidelines or your doctor’s advice.

Final thoughts...

Magnesium plays a key role in many of the body’s processes, including improving exercise performance, sleep, and mood – as well as boosting our muscle, heart, and bone health. If you don’t get enough of this essential mineral, your body can’t function properly, and magnesium deficiencies are linked to a range of health issues.

The best way to make sure you’re getting enough magnesium is to eat plenty of foods like nuts and seeds, dark green leafy veg, whole grains, and legumes. Though, if you’re unable to get enough magnesium from your diet, your doctor may recommend taking a supplement.

For more diet and nutrition advice, you might want to visit the diet and nutrition section of our website.

Do you feel like you’re getting enough magnesium in your diet? Or do you have any additional tips for staying healthy? We’d be interested to hear from you in the comments below.