Magnesium: A Science-Based Guide
What is magnesium?
Magnesium is an essential mineral involved in more than 300 enzymatic reactions in the body. It is the fourth most abundant mineral in the human body and plays a crucial role in many biological processes — from energy production to protein synthesis.
The body cannot produce magnesium on its own, so it must be obtained from food or supplements. Magnesium-rich foods include dark leafy greens, nuts, seeds, legumes, and whole grains. However, everyday dietary intake of magnesium may sometimes fall short of needs.
As a supplement, magnesium is available in various forms: tablets, capsules, powders, and drinks. In the European Union, only EFSA (European Food Safety Authority) approved health claims may be used in the marketing of magnesium supplements.
How does it work?
Magnesium acts as a cofactor in hundreds of enzymatic reactions. It is essential for ATP (adenosine triphosphate) production — ATP is the primary energy currency of cells, and magnesium stabilises the ATP molecule, enabling it to release energy.
In muscle function, magnesium works in coordination with calcium: calcium causes muscle contraction, while magnesium contributes to muscle relaxation. This balance is important for normal muscle function.
In nerve signal transmission, magnesium helps regulate the conduction of nerve impulses. It participates in modulating neuronal receptors and contributes to the normal functioning of the nervous system.
Magnesium also participates in protein synthesis, helping to combine amino acids into protein molecules — a process necessary for tissue repair and growth.
Supported benefits (EFSA-approved claims only)
The following benefits are based on health claims authorised under Commission Regulation (EU) No 432/2012. All claims are valid when the supplement provides at least 56.25 mg of magnesium (15% of the Nutrient Reference Value) per serving:
Tiredness and fatigue
- Magnesium contributes to a reduction of tiredness and fatigue — this is an EFSA-approved claim. Note that it is not permitted to say "eliminates fatigue" or "gives you energy".
Muscle function
- Magnesium contributes to normal muscle function — magnesium participates in the regulation of muscle contraction and relaxation. Note that claims such as "prevents cramps" or "eliminates muscle cramps" are not permitted.
Nervous system
- Magnesium contributes to normal functioning of the nervous system — magnesium participates in nerve impulse transmission. Claims such as "reduces anxiety" or "calms the nerves" are not permitted.
Electrolyte balance
- Magnesium contributes to electrolyte balance — magnesium is one of the main electrolytes in the body alongside sodium, potassium, and calcium.
Energy-yielding metabolism
- Magnesium contributes to normal energy-yielding metabolism — magnesium is necessary for ATP production and energy-releasing metabolic processes.
Protein synthesis
- Magnesium contributes to normal protein synthesis — magnesium participates in combining amino acids into protein molecules, which is necessary for tissue repair and growth.
Important note: Claims such as "reduces anxiety", "helps sleep", "prevents cramps", "treats migraines", or "strengthens bones" are not EFSA-approved health claims for magnesium. These are either insufficiently supported by scientific evidence or are medical claims that may not be used for food supplements.
Forms of magnesium
Magnesium supplements are available in different chemical forms. Each form differs in bioavailability and characteristics:
Magnesium citrate
A compound of magnesium and citric acid. Good bioavailability, widely available, and well-studied. A popular choice on the Estonian market due to its good price-to-quality ratio.
Magnesium glycinate (bisglycinate)
A chelated compound of magnesium and the amino acid glycine. Known for good gastrointestinal tolerance. Increasingly popular on the Estonian market.
Magnesium malate
A compound of magnesium and malic acid. A well-absorbed form that is often preferred by active athletes.
Magnesium oxide
Contains the highest amount of elemental magnesium per unit mass, but bioavailability is comparatively low. Often used in more affordable supplements.
Magnesium taurate
A compound of magnesium and the amino acid taurine. A relatively newer form on the market.
Magnesium threonate
A compound of magnesium and threonic acid. A newer form for which research is still actively being conducted.
On the Estonian market, the most common forms are magnesium citrate and magnesium glycinate (bisglycinate). When choosing a form, consider personal preferences and tolerance. The most important factor is the magnesium content per serving, as stated on the product label.
How to take it
Magnesium is recommended to be taken with food, which improves absorption and reduces gastrointestinal discomfort.
Guidelines:
- Always follow the recommended daily serving stated on the label — do not exceed it
- Take magnesium with a meal to improve absorption
- The European Food Safety Authority has set the tolerable upper intake level for magnesium from supplements for adults at 250 mg per day — this is not a recommended dose but an upper safety limit for supplemental magnesium (no upper limit has been set for magnesium from food)
- The daily dose can be split into several smaller doses, which may improve tolerance and absorption
- Some people prefer to take magnesium in the evening, others in the morning — timing is a matter of personal preference
- Powder form mixed with water can offer a convenient alternative to tablets
Practical tip: If you are starting magnesium supplementation for the first time, it may be wise to begin with a smaller dose and increase gradually to allow the digestive system to adjust.
Who should use it?
A magnesium supplement may be relevant for adults who want to ensure adequate daily magnesium intake.
Magnesium supplementation may be of interest to:
- Athletes and physically active individuals — magnesium contributes to normal muscle function and electrolyte balance, which is particularly important during intense training when magnesium losses through sweat increase
- People experiencing fatigue — magnesium contributes to a reduction of tiredness and fatigue
- Residents of northern countries — in northern climates where seasonal dietary patterns vary, magnesium intake from food may be insufficient
- Office workers and people with mental workloads — magnesium contributes to the normal functioning of the nervous system
- People with a limited diet — a restricted food selection may lead to insufficient magnesium intake
Who should exercise caution:
- People with severe kidney function impairment — the kidneys regulate magnesium levels in the body
- People taking certain medications (e.g., some antibiotics, diuretics) — consult your doctor regarding potential interactions
When in doubt, consult your doctor.
Frequently Asked Questions
What is the difference between different forms of magnesium?
Magnesium supplements come in various chemical forms (citrate, glycinate, malate, oxide, etc.). They differ in bioavailability and tolerance. Citrate and glycinate are generally better absorbed than oxide. The most important factor is the magnesium content per serving, not just the form name.
Can I take too much magnesium?
EFSA has set the tolerable upper intake level for magnesium from supplements for adults at 250 mg per day. Excessive intake may cause gastrointestinal discomfort (primarily a laxative effect). Always follow the recommended dosage on the label.
When is the best time to take magnesium?
Magnesium can be taken at any time of day — morning, midday, or evening. The important thing is to take it with food to improve absorption. Choose a time that fits your daily routine and helps you remember consistently.
Can I take magnesium with other supplements?
Yes, magnesium can generally be combined with other supplements. However, magnesium may affect the absorption of certain minerals (such as iron and zinc) when taken at the same time in large amounts. If you take medications, consult your doctor.
Can I get enough magnesium from food?
Magnesium-rich foods include dark leafy greens, nuts (especially almonds and cashews), seeds, legumes, bananas, and whole grains. If your diet is varied and regularly includes these foods, you may get sufficient magnesium from food. A limited diet, however, may lead to insufficient intake.
Why do some people experience digestive upset when taking magnesium?
Some magnesium forms (especially magnesium oxide and citrate) may have a laxative effect in larger doses. If you experience gastrointestinal issues, try smaller doses by splitting the daily amount across multiple servings, or switch to a different form (for example, magnesium glycinate is generally gentler on the digestive system).
---
See also:
