Magnesium is an important nutrient for both overall health and physical performance. A bit of an unsung hero, it plays a role in more than 300 bodily processes.1
Let’s look deeper into the world of magnesium to find out its functions, how it can support health and performance, and how to make sure you’re getting enough of it.
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What is magnesium?
Magnesium is an essential micronutrient that we must consume plenty of for our bodies to function properly. We don’t require it in the same amounts as we do macronutrients like carbs, fats, and protein, but it does play a crucial role in many bodily processes, from DNA creation and muscle and nerve function to maintaining blood pressure and blood glucose levels.1,2
What does magnesium do?
Magnesium is involved in many physiological processes, including:
What are the signs of low magnesium?
Low magnesium can silently disrupt critical functions, resulting in symptoms like nausea, muscle cramps, constipation, sleep disturbances, fatigue, and heart palpitations.2,9
Sometimes called an "invisible deficiency," low magnesium levels can be difficult to diagnose through blood tests as less than 1% of magnesium resides in the blood. The majority is stored in bone, muscle, and tissue.2
What can cause magnesium deficiency?
Research has shown that those who are active appear to be at risk of magnesium deficiency with one study finding that athletes who participate in weight-making sports like wrestling or gymnastics are particularly vulnerable to deficiency.10,11
This is likely due to the effect severe calorie restriction has on micronutrient intake, which can lead to low magnesium levels.
Other things that can also lead to low magnesium include excessive vomiting, digestive conditions, and alcohol abuse.
Periods of vomiting
Magnesium is considered an electrolyte, which can be lost through frequent vomiting and excessive sweating.
Digestive conditions
Gastrointestinal disorders can lead to low levels of certain nutrients due to malabsorption, often resulting from damage to the intestines.
Eating disorders
Magnesium levels can be low due to reduced dietary intake or periods of vomiting. They can also drop due to refeeding syndrome, which can occur as a result of fast refeeding following a period of undernutrition.
Alcohol abuse
Chronic alcohol misuse has been associated with low levels of electrolytes such as phosphate, potassium, and magnesium.12,13 These are thought to be caused by toxins within the bloodstream and the diuretic effect of alcohol.13,14
Health benefits of magnesium
Magnesium can support performance
Magnesium is particularly important for athletes as it is involved in the reactions that are required for protein synthesis, energy production, and recovery from oxidative stress.15
Carbohydrates are the body’s preferred fuel source, and the rate at which we use them during exercise increases. Research has shown that magnesium can enhance exercise performance as it can increase glucose availability in the muscles, blood, and brain.16,17,18
Magnesium can also prevent lactate levels building up in the muscles as it increases the rate of lactate clearance, which is associated with improved performance and delays pain and fatigue in the muscles.16,19,20
Magnesium can also enhance recovery, which can impact your performance in subsequent sessions. One recent study found that magnesium supplementation significantly reduced muscle soreness and improved perceived recovery.21 However, this was a small sample size and more research is needed within this area to confirm the mechanisms and appropriate dosages.
Magnesium can support sleep
Magnesium has also been shown to support sleep, particularly for those with insomnia and there are a few possible mechanisms for this.22
As magnesium supports neurotransmitter function, which send signals throughout the nervous system and brain, it can help to activate the parasympathetic nervous system, which helps us to relax and wind down.23 Magnesium also binds to neurotransmitter gamma-aminobutyric acid (GABA) receptors, which helps to calm brain activity.24
Melatonin is a hormone that helps to regulate our sleep cycle, and magnesium is an important nutrient, alongside B vitamins and zinc, for its synthesis.25 Deficiencies in magnesium have been linked with lower melatonin levels.26,27
In a study on elderly people, it was found that those who were given 500mg of magnesium had higher levels of melatonin and saw significant improvements in sleep efficiency and quality.26 Other studies have supported this finding that magnesium may improve markers of insomnia.28
Magnesium can support heart health
High blood pressure, or hypertension, is associated with an increased risk of cardiovascular-related events like heart attack and stroke, as well as kidney disease and even more serious conditions.29
Low dietary intake of magnesium has been associated with an increased risk of developing hypertension, and some evidence has highlighted that magnesium supplementation may help to lower blood pressure. A recent meta-analysis of over 20,000 people found that magnesium had a significant effect on lowering blood pressure.30 The mechanisms for this remain unclear, but it is expected that this effect is linked to magnesium lowering intracellular sodium and calcium, which increase blood pressure, and also play a role in relaxing blood vessels.31,32
However, the evidence for the use of magnesium supplementation to reduce blood pressure is mixed, with some suggestions that magnesium coupled with potassium and a reduced sodium intake may be more effective in reducing blood pressure than magnesium alone.33
The current consensus is that despite encouraging evidence, there needs to be more randomized controlled trials to prove a direct link between increased magnesium intake and reduced blood pressure before it can be considered for use in hypertensive individuals.
Always consult your GP for bespoke advice and if you have any concerns regarding your blood pressure.
Magnesium can protect your bones and joints:
Approximately 60% of the body’s total magnesium is stored in the bone.34 Studies have shown that supplementing magnesium can enhance bone mineral density and this may help to keep bones strong during the aging process.35,36,37
In an observational study that included over 73,000 postmenopausal women, who are at risk of reduced bone density due to the drop in estrogen during this stage, it was found that those with a higher magnesium intake had 2-3% higher bone density than women who had half of this amount.38
Magnesium may improve menstrual cramps:
Magnesium plays a role in muscle contractions and can help to prevent muscle cramps. Recent evidence has shown that it may also have a role in the reduction of PMS symptoms, predominantly period cramps and bloating.39 Magnesium can help to calm the nervous system and can reduce prostaglandins that cause period pain as well as helping to relax the muscles of the uterus.39,40,41
One study identified that magnesium supplements alongside vitamin B6 supplementation worked better than taking magnesium supplements alone, but both the magnesium and magnesium and B6 groups were more effective in reducing PMS symptoms than the placebo.42
What are good sources of magnesium?
- Avocados
- Beans and legumes
- Dark chocolate
- Fish
- Nuts and seeds
- Spinach and other leafy greens
- Tofu
- Whole grains
The best magnesium supplements to take
Magnesium Citrate Powder
This powder is a super easy way to supplement magnesium in your diet and is often vegan-friendly too.
Zinc & Magnesium Tablets
Capsules that contain vitamin B6 and zinc as well as magnesium provide even more benefits such as supporting immunity, improving energy levels, and supporting the maintenance of bone and muscle tissue.
Peanut butter
Nuts are a great source of magnesium, and topping your toast or oatmeal with peanut butter can help to boost your intake.
FAQs about magnesium
When is the best time to take magnesium?
Whenever you remember to and is most convenient for you. If you take it as a powder, you can add it to a protein shake, or if you take it in tablet form, you can have it alongside your other supplements.
Can you take magnesium supplements every day?
Yes, you can take magnesium supplements every day, as long as you don’t exceed the recommended dose.
Can you have too much magnesium?
Too much magnesium can lead to nausea, diarrhea, and low blood pressure. It can be serious, so do not exceed recommended doses and seek professional advice if you think you may be experiencing symptoms.
If you are taking magnesium supplements, be sure not to take more than advised. The Department for Health and Social Care advises that up to 400mg of magnesium from supplements is unlikely to cause harmful effects.43
What type of magnesium is best for sleep?
Different forms of magnesium are available as supplements, and magnesium citrate and glycinate are the most common. Magnesium citrate is magnesium bound with citric acid, while magnesium glycinate is magnesium bound with the amino acid glycine. Magnesium glycinate is often suggested for improvements with sleep.44
What type of magnesium is best for after exercising?
Magnesium citrate is the most bioavailable form of magnesium supplements, meaning that it is the easiest for the body to absorb. It has also been shown to support muscle contraction and relaxation.45,46
Does coffee deplete magnesium?
While coffee does not directly affect magnesium, the tannins in it can decrease absorption. Excessive intake of caffeine can also have a diuretic effect and therefore reduce magnesium within the body.
Avoid taking magnesium supplements with your morning coffee wherever possible.
Take home message
Magnesium is a powerhouse mineral that contributes to so many functions in the body, which is why it’s important to include plenty of nuts, seeds, and leafy greens in your diet to ensure that you’re getting enough of it.
Active people are at particular risk of low magnesium, so may benefit from a supplement, which can support health, performance, and recovery.
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