Magnesium is the second most abundant mineral in the body and plays an essential role in the musculoskeletal and nervous systems, as well as mediating over 300 biochemical reactions and metabolic processes by acting as an enzyme cofactor.

The total body magnesium content in adults is approximately 24g, 99% of which is found within the cells, with just 1% circulating in the blood. The majority is stored in bone (contributing to the density and strength of the skeleton), muscle (contributing to muscle contractions) and soft tissue (especially in organs that are most metabolically active, such as the brain, heart, liver), and kidneys, reflecting magnesium’s critical role in energy production. Bone tissue is by far the largest magnesium store and functions as an easily accessible reservoir when magnesium intake is low. Prolonged inadequate magnesium intake can result in bones being ‘leached’ of magnesium reserves, and is a risk factor for osteoporosis. 

Magnesium acts as a cofactor for a number of enzymes involved in energy production. ATP (the main energy currency used for all metabolic processes), for example, cannot function unless it is joined to magnesium. As such, low magnesium status is often associated with conditions in which fatigue is a key symptom. 

Deficiency of magnesium is linked to various disorders, including cardiovascular (e.g. heart failure, arrhythmia, heart attack, stroke and hypertension), musculoskeletal (muscle spasms & cramps, osteoporosis), gastrointestinal (constipation) and central nervous system (e.g. insomnia, anxiety, depression, chronic fatigue syndrome and impaired cognitive function) disorders.  

Magnesium homeostasis is controlled by the intestines, bones and kidneys. Of the total dietary magnesium consumed, between 24–76% is absorbed in the gut and the rest is eliminated in the faeces. Many factors influence magnesium absorption; however, regardless of the source, studies show that certain foods can restrict magnesium absorption in the human body. For example, high-protein diets can decrease magnesium absorption; tannins present in tea can bind magnesium, making it unavailable for absorption. Presence of oxalates in certain vegetables (e.g. rhubarb, spinach and chard) and phytates in cereals and legumes can also reduce the absorption of magnesium by up to 60%. In contrast, consumption of fermentable dietary fibre, such as fructooligosaccharides found in bananas, onions, chicory root, garlic, asparagus and leeks can enhance magnesium absorption by 10-25%.

The health benefits of magnesium are well established, and supplementation can both relieve active symptoms and support systems to prevent chronic illness from developing or worsening.

Magnesium contributes to: 

• a reduction of tiredness and fatigue 
• electrolyte balance
• normal energy-yielding metabolism
• normal functioning of the nervous system
• normal muscle function
• normal protein synthesis
• normal psychological function
• the maintenance of normal bones and teeth
• the process of cell division 

Magnesium is widely distributed in foods of plant and animal origin, with tap & bottled water making a significant contribution to dietary magnesium intake (higher in hard water than in soft water). As chlorophyll is the magnesium chelate of porphyrin, green leafy vegetables are particularly rich in magnesium. Vegetables, grains and nuts generally have a higher magnesium content than animal products. Given that the UK population fails to achieve the 5-a-day target for vegetable intake, it is likely (as seen in the USA, where magnesium intake is <50% of requirements) that intake is insufficient to meet requirements.

Magnesium is found in high quantities in dark chocolate, avocados, nuts (especially almonds, cashews and Brazil nuts), seeds (e.g., flax, pumpkin and chia seeds), whole grains & pseudograins (e.g., buckwheat and quinoa), legumes, tofu, leafy greens and even fatty fish. 

Refining and processing of food can deplete magnesium content by up to 85%, and cooking (especially boiling) also results in a significant loss of magnesium. As the intake of refined foods increases (as seen in developed countries), magnesium deficiency will most likely evolve into a more common disorder. 

It is noteworthy that insufficiency in additional nutrients will also affect magnesium levels. For example, the synergistic relationship between vitamin D and magnesium also sheds light on the low magnesium status common in the UK. Vitamin D at physiological doses enhances magnesium absorption, and adequate levels of magnesium are essential for the absorption and metabolism of vitamin D to calcitriol. Thus, suboptimal intake of vitamin D (known to be common in the UK) or magnesium will have a number of potential health consequences.

With rates of magnesium deficiency already high and on the increase, and the benefits of magnesium supplements well established, it is clearly a priority to choose the most effective magnesium product for use in clinical practice, in order to have the greatest impact on improved health.

When considering what makes an effective magnesium supplement, the following factors should be taken into account, because they directly influence its bioavailability, tolerability and overall efficacy.

In contrast to magnesium salts, magnesium ‘chelates’, such as glycinate and taurate, bypass ion channels and are instead absorbed in the same way that dietary amino acids are absorbed from the gut.  The bond that joins magnesium to an amino acid is incredibly strong and works in favour of magnesium absorption because, as the amino acid crosses the cell membrane, it pulls magnesium in after itself, giving magnesium a ‘free ride’.  The benefit of the chelate doesn’t end there.  When considering the absorption of a magnesium salt, when the magnesium ion is liberated from the salt, unless it is immediately absorbed by an ion channel, it remains extremely vulnerable, attracting water and becoming too big to be absorbed, or forming bonds with compounds found in food (oxalates and phytates) and becoming insoluble. 

Furthermore, these three forms of magnesium create a favourable acidic environment that protects free magnesium ions from interacting with food or water that would otherwise interfere with magnesium uptake, thereby enhancing the absorption of free ions.

Magnesium supplements are generally available in three formats: blends, buffered formulations and fully reacted forms.

Historically, magnesium oxide has often been used as an inexpensive source of elemental magnesium because it contains a very high percentage of magnesium by weight. When used alone, however, magnesium oxide is relatively insoluble and is typically less readily absorbed than fully reacted magnesium salts and chelates.

Well-designed buffered magnesium formulations take a different approach. Rather than relying solely on magnesium oxide, they combine fully reacted magnesium forms with magnesium oxide to increase the elemental magnesium content. This allows a higher elemental magnesium dose to be delivered in fewer capsules while still providing highly absorbable magnesium from the reacted forms.

Neither approach is inherently "better" - the most appropriate choice depends on your individual needs. Fully reacted magnesium prioritises maximum solubility and digestive comfort, whereas buffered magnesium aims to balance high elemental magnesium delivery with the benefits of highly absorbable magnesium forms.

When assessing a magnesium supplement, it is therefore important to look beyond the headline elemental magnesium figure. The forms of magnesium used, the formulation strategy and the intended purpose of the product all influence how effectively that magnesium can support magnesium status.

The importance of dosing strategy

The majority of ingested magnesium is absorbed in the small intestine, and it is well established that taking smaller, divided doses generally results in greater overall absorption than consuming the same amount in a single large dose. When a high dose is taken at once, the gut's normal absorption mechanisms become saturated, meaning a smaller proportion of the magnesium is absorbed and retained.

Studies have shown that magnesium absorption from a low elemental dose can be as high as 65%, whereas doses exceeding 250 mg may have relative absorption rates of around 20–25%. For this reason, spreading magnesium intake across the day is often considered the most efficient way to optimise magnesium status.

Our Triple Magnesium Complex has therefore been formulated to be taken as two divided doses, each providing 131 mg of fully reacted magnesium. This approach helps maximise absorption and retention while providing a steady supply of magnesium throughout the day.

Pure & Essential Magnesium Glycinate has been formulated to support a different approach to supplementation. While split dosing may optimise magnesium absorption, many people prefer to take magnesium glycinate as a single evening dose because magnesium supports normal nervous system function, and glycine has been studied for its potential to promote relaxation and healthy sleep. Although this approach may result in slightly lower magnesium absorption than dividing the dose, it offers the convenience of a simple bedtime routine and provides the full bisglycinate serving at the time many people choose to support relaxation.

The form of magnesium you choose influences not only its absorption but also how it best fits your individual health goals and lifestyle.

Whether you choose Pure & Essential Magnesium Glycinate, formulated around Albion® TRAACS® magnesium bisglycinate chelate, or Triple Magnesium Complex, which combines three fully reacted magnesium forms, selecting a high-quality, well-formulated magnesium supplement is key to supporting optimal magnesium status.

Pure & Essential Magnesium Glycinate provides highly absorbable magnesium in bisglycinate form within a carefully designed buffered formulation, making it an excellent choice for evening supplementation, particularly for those looking to support relaxation, healthy sleep, muscle function and nervous system health.

Triple Magnesium Complex provides 262 mg of fully reacted magnesium from citrate, bisglycinate and taurate, making it an excellent choice for those seeking a completely fully reacted formulation without added magnesium oxide. While both buffered and fully reacted formulations can effectively support magnesium status, our nutritionists generally recommend a fully reacted magnesium supplement for individuals with particularly sensitive digestive systems, or for those looking to prioritise maximum solubility and digestive comfort.

Ultimately, no single magnesium formulation is right for everyone. Understanding the differences between magnesium forms, formulation strategies and dosing approaches allows you to choose the supplement that best matches your individual needs, helping you get the greatest benefit from magnesium supplementation.

Shop by nutrient > magnesium to view the Igennus range of supplements.