Magnesium is sometimes overlooked alongside better-known nutrients, but it has a wide range of important functions throughout the body. From energy metabolism and muscle function to the nervous system and bones, maintaining an adequate magnesium intake is an important part of a balanced diet.

This guide explores the role of magnesium, how much we need, dietary sources, different forms of magnesium and what to consider when choosing a magnesium supplement.

What is Magnesium?

Magnesium is an essential mineral that the body needs to function normally. It is found naturally in many foods and is also available in food supplements.

Within the body, magnesium contributes to a wide range of normal physiological processes. These include normal energy-yielding metabolism, muscle function, protein synthesis, psychological function and the functioning of the nervous system. It also contributes to electrolyte balance and the maintenance of normal bones and teeth.

Because the body cannot produce magnesium itself, it needs to be obtained through the diet.

What Does Magnesium Do in the Body?

Energy & Tiredness

Magnesium contributes to normal energy-yielding metabolism, helping the body release energy from the food we eat. It also contributes to the reduction of tiredness and fatigue.

This makes magnesium an important nutrient for normal everyday energy metabolism, rather than something that provides an immediate energy boost.

Muscle Function

Magnesium contributes to normal muscle function and normal protein synthesis. It also contributes to electrolyte balance, another important part of normal physiological function.

Muscle contraction and relaxation involve several minerals, including magnesium and calcium. This is one reason magnesium is frequently associated with exercise and active lifestyles, although its role in normal muscle function is important for everyone.

Nervous System & Psychological Function

Magnesium contributes to the normal functioning of the nervous system and normal psychological function.

Magnesium is often associated with relaxation, stress and sleep. While its recognised roles in normal nervous system and psychological function help explain this interest, these should not be interpreted as meaning that magnesium supplements will necessarily improve sleep or relieve stress or anxiety.

Bone & Teeth

Although calcium and vitamin D are often the nutrients most closely associated with bones, magnesium also contributes to the maintenance of normal bones and teeth.

Around 50 to 60% of the magnesium in the adult body is found in bone, with most of the remainder located within soft tissues.

Protein Synthesis & Cell Division

Magnesium also contributes to normal protein synthesis and has a role in the process of cell division.

Together, these recognised functions show why magnesium is required throughout the body and why obtaining an adequate amount as part of a balanced diet is important.

What Happens If Magnesium Intake Is Too Low?

Most people can obtain magnesium from a varied, balanced diet, but consistently low intake can eventually affect magnesium status. True magnesium deficiency is uncommon in otherwise healthy people because the body can regulate magnesium levels to some extent, including by reducing the amount lost through the kidneys.

When magnesium deficiency does occur, early signs can include loss of appetite, nausea, fatigue and weakness. More severe deficiency can affect normal nerve and muscle function and may lead to symptoms such as muscle contractions or cramps, numbness, tingling and abnormal heart rhythms.

Certain health conditions and medicines can also affect magnesium levels or increase magnesium losses. Anyone concerned that they may have a magnesium deficiency should speak to a healthcare professional rather than relying on symptoms alone.

How Much Magnesium Do You Need?

The amount of magnesium needed varies according to age and sex. In the UK, the Reference Nutrient Intake (RNI) for adults is 300mg per day for men and 270mg per day for women.

These figures represent the amount considered sufficient to meet the needs of most people and include magnesium obtained from food and drink.

A varied diet containing foods such as green leafy vegetables, nuts, seeds, whole grains and legumes can contribute towards daily magnesium intake. Supplements can provide an additional source, but they should complement rather than replace a varied, balanced diet.

Top Ten FAQs - Magnesium

What does magnesium do in the body?

Magnesium contributes to normal energy-yielding metabolism, muscle function, protein synthesis, psychological function and the normal functioning of the nervous system. It also contributes to electrolyte balance and the maintenance of normal bones and teeth.

How much magnesium do adults need each day?

In the UK, the Reference Nutrient Intake (RNI) for magnesium is 300mg per day for adult men and 270mg per day for adult women. A varied, balanced diet can provide magnesium from a range of foods.

What foods are naturally high in magnesium?

Magnesium is found in foods including green leafy vegetables, nuts, seeds, whole grains, beans and lentils. Avocado, dark chocolate and some fish can also contribute to dietary magnesium intake.

What is the difference between magnesium bisglycinate, citrate and malate?

They are different compounds used to provide magnesium in supplements. Bisglycinate combines magnesium with glycine, citrate combines it with citric acid, and malate combines it with malic acid. Different formulations may use one form or combine several forms within the same supplement.

What does elemental magnesium mean?

Elemental magnesium refers to the actual amount of magnesium supplied by a magnesium compound. For example, the total weight of magnesium bisglycinate or magnesium citrate listed in a formulation is not necessarily the same as the amount of elemental magnesium it provides.

When is the best time to take magnesium?

There is no single time of day that is right for everyone. Follow the directions provided with your chosen supplement and choose a time that fits consistently into your routine. Some magnesium products are recommended to be taken with food.

Can I take magnesium every day?

Magnesium is an essential nutrient needed every day and is naturally obtained through the diet. Magnesium supplements can also be designed for daily use, but you should follow the recommended intake on the individual product and avoid exceeding the stated amount.

Does magnesium help with sleep and relaxation?

Magnesium contributes to normal functioning of the nervous system and normal psychological function. Although magnesium supplements are commonly associated with sleep and relaxation, these recognised functions should not be interpreted as meaning that magnesium will necessarily improve sleep or relieve stress or anxiety.

Can magnesium supplements cause side effects?

Supplemental magnesium can cause gastrointestinal effects such as diarrhoea, nausea or abdominal discomfort in some people, particularly at higher intakes. Always follow the recommended intake provided with the supplement.

Can magnesium interact with medication?

Magnesium can interact with certain medicines, including some antibiotics and medicines used to treat osteoporosis. If you take prescribed medication or are under medical supervision, speak to your doctor or pharmacist before taking a magnesium supplement.

Which Foods Are High in Magnesium?

Magnesium occurs naturally in a wide variety of foods, so a balanced diet can provide a significant proportion of your daily intake.

Green leafy vegetables such as spinach are useful sources because magnesium forms part of chlorophyll, the pigment that gives plants their green colour. Nuts and seeds, including almonds, cashews and pumpkin seeds, can also provide magnesium, alongside whole grains, beans, lentils and other legumes.

Magnesium is also found in foods such as avocado, dark chocolate and some fish, giving both plant-based and mixed diets plenty of ways to include the mineral.

Choosing a varied range of magnesium-containing foods has the added benefit of providing other important nutrients, including fibre, protein, vitamins and other minerals.

What Are the Different Forms of Magnesium?

Magnesium supplements are available in several forms, with magnesium combined with another compound to create ingredients such as magnesium bisglycinate, citrate, malate and oxide. The amount of elemental magnesium provided can vary between forms, so the total weight of a magnesium compound should not be confused with the amount of magnesium it actually supplies.

Magnesium Bisglycinate combines magnesium with the amino acid glycine. It is a popular form for everyday supplementation and is particularly common in products designed for evening routines.

Magnesium Citrate combines magnesium with citric acid and is one of the most widely used forms in magnesium supplements. It is commonly found in both capsules and powders.

Magnesium Malate combines magnesium with malic acid, a naturally occurring compound involved in normal energy-producing processes within the body. It is often included in magnesium formulas aimed at active or daytime routines.

Magnesium Oxide is another widely available form and can provide a relatively high proportion of elemental magnesium by weight, although different magnesium compounds vary in their characteristics.

There isn't one form of magnesium that is automatically the right choice for everyone. When comparing supplements, consider the form or forms used, the amount provided, serving size, additional ingredients and how the product fits into your routine.

Choosing a Magnesium Supplement

When choosing a magnesium supplement, it's worth looking beyond the number on the front of the pack. Magnesium supplements can contain different magnesium compounds, different combinations of forms and additional nutrients, so two products labelled as magnesium supplements may have quite different formulations.

Consider the forms of magnesium included, serving size, additional ingredients and dietary requirements, as well as whether you prefer capsules, tablets or another format. It's also important to distinguish between the total weight of a magnesium compound and the amount of elemental magnesium it provides.

Lily & Loaf offers several magnesium formulations to suit different preferences. Triple Magnesium combines magnesium bisglycinate, citrate and malate with vitamin B6, while Double Magnesium provides a different two-form magnesium formulation. We also stock Nature's Sunshine Magnesium, providing another option for customers who prefer Nature's Sunshine products.

Can You Take Too Much Magnesium?

Magnesium obtained naturally from food is not generally a concern for healthy people because the body regulates the amount it retains. Supplemental magnesium, however, can cause gastrointestinal effects such as diarrhoea, nausea and abdominal discomfort when taken in higher amounts.

Magnesium supplements can also interact with certain medicines, including some antibiotics and medicines used for osteoporosis. If you take prescribed medication, have an existing medical condition or are unsure whether a magnesium supplement is suitable for you, speak to a doctor or pharmacist before use.

Always follow the recommended intake provided with a food supplement and do not exceed the stated daily amount.

The Bigger Picture

Magnesium is an essential mineral with recognised roles throughout the body, contributing to normal energy metabolism, muscle function, nervous system function, psychological function and the maintenance of normal bones and teeth.

A varied, balanced diet containing foods such as leafy green vegetables, nuts, seeds, whole grains and legumes can provide magnesium naturally. For those who choose to supplement, magnesium is available in a variety of forms and formulations, making it useful to understand what a product contains rather than comparing supplements by headline numbers alone.

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Magnesium: A Comprehensive Guide