First of all, it’s worth restating the definition of magnesium. Magnesium is a mineral, one of the most abundant on the planet. It is found in soil, water, plants and animals. The human body contains an average of 25 grams, 50%-60% of which is concentrated in the bones, with the remainder distributed in soft tissue. Magnesium is also present in blood serum at concentrations of between 0.75 and 0.95 mmol/L, as well as in urine. Magnesium is used daily by the body for various functions or eliminated in urine. Therefore, in order to meet the body’s needs, magnesium must be ingested from either the diet or supplementation.
The magnesium intake of a sizeable percentage of the population is, however, lower than it should be, leading to shortfalls and actual deficiencies. Scientists call this hypomagnesaemia and it is diagnosed when an individual has:
Additional tests are often carried out to confirm hypomagnesaemia. For example, magnesium deficiency can be detected by analysing red blood cells (erythrocytes) and saliva.
As mentioned, the body needs magnesium in order to function properly. It plays a part in over 300 metabolic reactions. Magnesium is referred to as a cofactor which means its presence is required in order for various biochemical reactions to occur. In particular, it is recognised as contributing to energy production, nerve transmission, muscle relaxation, oxidative phosphorylation and glycolysis. It thus acts at various levels of the body and in multiple mechanisms:
This list is by no means exhaustive. Magnesium’s properties are so numerous that the body’s requirements for this mineral have to be satisfied every day!
Though magnesium is essential to health, the body cannot produce it and we therefore have to obtain it from external sources. Based on numerous studies, public health authorities have established the following nutritional recommendations. The recommended amount for an adult is on average 300g-450g a day. It’s important to note that recommended amounts for magnesium can vary from one person to another and requirements can also depend on several factors, including age and build. They may also increase in the case of repeated intense exercise, periods of stress and pregnancy.
By way of example, the daily magnesium intakes recommended by US health authorities are as follows:
Experts from the Food and Nutrition Board (FNB) of the American National Academy of Sciences, add that pregnant women should increase their daily intake of magnesium by 40mg.
Given its many roles in the body, a lack of magnesium can have numerous undesirable effects. A shortfall or deficiency can affect many parts of the body – the cardiovascular system, the muscles, the brain, the bones… This is why public health authorities are calling for vigilance, particularly as in many regions of the world, more than 75% of the population could be affected. In the US for example, the large-scale National Health and Nutrition Examination Survey (NHANES), conducted between 2005 and 2006, revealed that for the majority of Americans (all ages), magnesium intake was insufficient for their needs. Similarly, the French study SU.VI.MAX (Supplémentation en Vitamines et Minéraux Anti-oxydants) found that magnesium intake was inadequate in 72% of men and 77% of women.
The signs of low magnesium levels are sometimes mistaken for those of other problems. Indeed, a lack of magnesium can manifest in relatively common symptoms such as persistent fatigue, muscle weakness, loss of appetite, nausea and vomiting. However, these symptoms are only the first indications. As the magnesium deficit becomes more serious, verging on actual deficiency, it disrupts mineral homeostasis, potentially causing hypocalcaemia - a lack of calcium, and hypokalaemia – a lack of potassium. This can have numerous consequences such as numbness, tingling, shaking, muscle contractions, cramps, tetany (muscle spasms) heart rate issues, and coronary, behavioural and digestive problems.
As mentioned, a shortage of magnesium can affect the body’s levels of both calcium and potassium. This is because there is a direct connection between these three minerals. In order to function properly, the body needs a good balance between magnesium and calcium, magnesium and potassium, and potassium and calcium. This contributes to what scientists call ‘mineral homeostasis’ – the balance between the various mineral levels in the body; a deficit in magnesium, for example, can upset the overall balance. It is precisely to prevent such imbalances that multi-mineral supplements, such as MultiMineral Complex have been developed. In a single capsule, this supplement delivers highly-bioavailable forms of magnesium, calcium, potassium, chromium, iodine, boron, selenium, zinc, vanadium and silicon. Uptake and absorption of these minerals is enhanced by the presence of vitamin B3 from Bioperine®, an extract of ginger and digestive enzymes. Bioavailability is a key factor to consider when choosing a multi-mineral supplement. It’s important to note that poor absorption in the gut can be one of the causes of a lack of minerals, particularly magnesium.
Magnesium is an essential mineral – in other words, we need to obtain it from an external source. A lack of this mineral is therefore largely due to ingesting too little to cover our needs. It’s worth noting here that the body’s requirements for magnesium can increase under certain conditions, including periods of intense exercise or stress. Remember that magnesium plays a key role in energy production, nerve transmission and muscle relaxation. The body consumes a significant amount of magnesium when it is under stress, tired or engaged in exercise, etc.
Apart from inadequate consumption, exercise and chronic stress, other factors can contribute to decreased magnesium levels:
Given that inadequate intake is the main cause of low magnesium levels, it’s important to ensure a sufficient amount is ingested on a daily basis. A number of sources of magnesium exist to meet the body’s needs, including several everyday foods. An obvious source would be a natural, magnesium-rich mineral water, sometimes called magnesium water. Foods high in magnesium include pulses such as beans, seeds, nuts such as almonds, whole grains, algae such as sea lettuce, dark green leafy vegetables such as spinach, as well as wheat germ, brewer’s yeast, chocolate, coffee, molluscs and crustaceans. If you buy refined products, be aware that processing can often drastically reduce a food’s natural magnesium content. For example, while the bran and germ of grains contain magnesium, these are often removed during the refining process. It’s therefore better to opt for whole grains, and more generally, for home-cooked foods, using gentle cooking methods to preserve the food’s mineral content.
Even with the availability of all these different foods high in magnesium, studies show that for a large majority of the population, intake is still too low. Hence the development of specific formulations to meet all the body’s needs for magnesium, prevent or correct any deficiency and deliver magnesium’s benefits. On the one hand, there are ‘fortified’ products - foods and drinks to which magnesium has been added. On the other, advances in encapsulation techniques have enabled the development of magnesium supplements with excellent bioavailability such as OptiMag. This dietary supplement boasts eight different forms of magnesium for optimal absorption: magnesium malate, citrate, glycerophosphate, bisglycinate, pidolate, taurinate, aspartate and arginate.
Magnesium exists in the form of mineral salts. This means that the elemental magnesium denoted by the letters Mg is combined with another element. Depending on the combination, the elemental magnesium content and its bioavailability can vary. Care should therefore be taken when choosing a magnesium supplement. It’s also worth looking at the properties of the different magnesium salts as each has its own specific features and benefits. For example, the patented form magnesium malate is recognised as being effective for constipation, acting as an aluminium chelator and combatting certain types of pain, while magnesium chloride is known for its immune-stimulant properties.
There are a number of differences between the various magnesium supplements on the market. The dose depends on various parameters, including the strength of the supplement, the magnesium salt used, the presence of other bioactive compounds … It’s therefore important to refer to the recommendations for use given for each product. The daily dose can also depend on your needs and your magnesium status. If you have any doubts, seek advice from a specialist. It’s also worth knowing that you can increase the absorption of a magnesium supplement by combining it with other active principles such as pyridoxamine. This natural form of vitamin B6 is known not only for promoting absorption of magnesium in the gut but also for its ability to increase energy production, its immune-stimulant effect and its antioxidant activity which gives it protective and anti-ageing effects. A magnesium/vitamin B6 combination is often popular with those suffering from chronic fatigue, sports enthusiasts looking for increased energy during exercise and those who want to fight the effects of ageing.
Is there a risk of over-dosing?
Hypermagnesaemia – excess magnesium levels – is extremely rare. It can cause side effects such as muscle weakness but these normally only develop in cases of kidney failure. As major organs of the urinary system, the kidneys eliminate excess mineral salts. In other words, the body is able to regulate its mineral levels and prevent any overdose. Of course, it’s still wise to follow the recommended doses for the product. If in doubt, you are strongly advised to seek medical guidance.
Are there any contra-indications?
Essential to health, magnesium is very well-tolerated by the body.However, as explained, magnesium supplementation is contraindicated in those suffering from kidney failure. Caution should also be applied when taking supplements alongside drugs containing magnesium or diuretics such as amiloride. Be sure to contact your doctor if you have any doubts about such interactions.
What are the key points to remember about inadequate magnesium levels?
This article contains a great deal of information on inadequate magnesium levels. In summary then, it’s important to remember that this is a much more common problem than you might think. Many people may be affected without realising it, particularly if they are subject to chronic stress, suffer from major fatigue, or engage in intense physical activity. Fortunately, prevention and treatment options are available. Alongside a healthy, balanced diet, magnesium supplements are one such option, their benefits having been confirmed by several scientific studies. In the United States, researchers have shown that adults who take supplements have much higher magnesium levels than the rest of the population. Since 2012, European public health authorities have taken a position on certain health claims relating to food and dietary supplements that contain magnesium. If the products contain at least 56mg of magnesium per 100g or 100ml, they may contribute to normal energy metabolism, normal function of the nervous system and muscles, the body’s electrolyte balance, protein synthesis and normal cell division, normal psychological function, maintenance of bones and teeth and the reduction of fatigue.
NB: Magnesium salts continue to be the subject of numerous studies. New findings may either contradict or complement those reported in this article. If in doubt, consult a health professional.
Taurine gets something of a bad rap. But did you know that it’s naturally produced by the body? Discover the (unexpected) effects of this substance – particularly on sleep
Whey is a powdered protein complex popular in the world of sports nutrition. Here we take a look at the efficacy of these proteins and how they can help maximise your body’s performance and athleticism.
“Walking is man’s best medicine.” So said Hippocrates in 400BC. Was he right? Let’s explore whether exercise really does improve the body’s defences.