Magnesium is one of the most important micronutrients for the human body; it participates in numerous physiological pathways and is essential for maintaining the normal functioning of cells and organs.

Given its significance, it is the fourth most abundant mineral in our body. 99% of total body magnesium is located in the intracellular compartment, of which 60% is found in the bones, 20% in the muscles, and 20% in other tissues.

It is key for the transfer of phosphate groups, all reactions requiring ATP, and every step related to DNA replication and transcription, as well as mRNA translation.

It also participates in the transfer, storage, and utilization of energy, regulating and catalyzing more than 300 enzymatic systems, ranging from brain function and mood stability to bone physiology.

Magnesium is fundamental for maintaining muscle function and the nervous system, cardiac electrical properties, and for supporting the immune system, in addition to regulating glucose and insulin metabolism.

The gastrointestinal tract, bones, and kidneys are the primary regulators of magnesium homeostasis; however, despite the presence of this complex system, various physiological and pathological conditions can lead to magnesium deficiency in the general population.

• Malabsorption, for example, inflammatory bowel disease, celiac disease, intestinal resection, bariatric surgery, etc.

• Prolonged use of certain medications such as diuretics, proton pump inhibitors, antibiotics, chemotherapeutics, corticosteroids, antacids, and insulin.

• Accelerated intestinal transit due to laxative abuse, diarrhea, or vomiting.

• Excessive sweating or hyperhidrosis.

• Alterations in hormonal pathways that regulate nutrient absorption, for example in situations of obesity, polycystic ovary syndrome, type II diabetes, metabolic syndrome, or systemic inflammation.

• Inadequate intake due to malnutrition, restrictive or selective eating, poorly planned diets, etc.

• Increased requirements due to pregnancy, sports, pathologies, among others.

These can cause subclinical magnesium deficiency and an increase in magnesium requirements.

Drinking water accounts for approximately 10% of daily magnesium intake, and chlorophyll, derived from green vegetables, is the primary dietary source of magnesium. Nuts, seeds, and unprocessed grains are also rich in magnesium.

It is important to mention that processed foods have a much lower magnesium content than whole grain products and that dietary magnesium intake in the Western world is decreasing precisely due to the consumption of processed foods.

With the ubiquity of processed foods, boiling, and the consumption of demineralized soft water, most industrialized countries are deprived of their natural supply of magnesium.

Magnesium supplements thus emerge as an alternative to complement dietary sources of magnesium.

To date, there are three main approaches available for clinical testing. The most common test for evaluating magnesium levels and status in patients is serum magnesium concentration, which is valuable in clinical medicine, especially for the rapid assessment of acute changes in magnesium status.

However, serum magnesium concentration does not correlate with tissue stores, with the exception of interstitial fluid and bone. It also does not reflect total body magnesium levels.

Only 1% of total body magnesium is present in extracellular fluids, and only 0.3% of total body magnesium is found in serum, which is why serum magnesium concentrations are poor predictors of intracellular/total body magnesium content.

And as with many reference values for other nutrients, laboratory parameters will also vary from one lab to another, resulting in slightly variable ranges for "healthy" populations. What is considered the "normal level" could actually be slightly too low, representing a mild magnesium deficiency present in the normal population.

Magnesium, being involved in so many processes, can provide indications of deficiency in various ways, the most common being fatigue, headache, muscle pain, depression, and difficulty falling asleep, among others.

Among the key factors influencing the efficacy of magnesium supplementation is the chemical form in which it is administered. The bioavailability of magnesium supplements (the proportion of magnesium that the body absorbs and uses) varies considerably depending on its solubility and molecular composition.

Organic forms, such as magnesium citrate, glycinate, lactate, threonate, and malate, involve magnesium chelated to organic molecules like amino acids or organic acids. These forms are generally more soluble and have higher bioavailability.

Inorganic forms, such as magnesium oxide, sulfate, and chloride, are bound to inorganic salts and tend to have lower solubility and absorption rates.

Due to the above, it is necessary for the form of magnesium used in supplementation to be indicated and personalized to fit specific health considerations.

Magnesium L-threonate is capable of crossing the blood-brain barrier, providing benefits for the nervous system and brain functions. Research suggests that it can improve memory and cognitive function. It has also been shown to have beneficial effects on sleep quality in humans.

Magnesium citrate is commonly used to correct deficiencies and support digestion, as it helps with intestinal motility and transit.

Magnesium Glycinate, chelated with the amino acid glycine, is well absorbed and is known for its calming effects, which are beneficial for people experiencing stress, anxiety, or sleep disorders.

Magnesium Taurate is well absorbed and is usually combined with taurine, an amino acid known for its cardiovascular benefits. It stands out for its potential to support heart health, helping to regulate blood pressure, maintain a stable heart rate, and promote overall cardiovascular function.

Magnesium Malate is a form of Magnesium chelated with malic acid, a compound involved in the Krebs cycle, the process by which the body produces energy. Consequently, it has been suggested that this combination is beneficial for energy production and muscle function.

Magnesium Chloride: Has moderate bioavailability and is available in oral and topical forms. It is commonly used for muscle relaxation and electrolyte balance. Topical application allows for magnesium absorption through the skin, although its efficacy remains controversial.

Magnesium Sulfate: Known as Epsom salt, it is used to treat hypomagnesemia, prevent seizures in eclampsia, and manage constipation. It acts by regulating magnesium levels, and its effects vary depending on the route of administration. It can cause side effects such as flushing or hypotension and is contraindicated in cases of heart block or hypersensitivity.

Magnesium Oxide: Contains a high percentage of elemental magnesium, but its solubility is low, which hinders its absorption. It is used primarily for short-term relief of constipation and heartburn rather than for addressing magnesium deficiencies.

Magnesium Carbonate: It is a common over-the-counter remedy for heartburn and indigestion caused by excess stomach acid. However, it should only be used for short-term relief, as prolonged use can cause digestive discomfort.

Magnesium plays an essential role in multiple physiological processes, from neuromuscular function and energy production to metabolic and cardiovascular balance. Understanding its sources, absorption mechanisms, and the differences between its various forms allows for making informed decisions and tailoring supplementation to individual needs and health goals.

Each form of magnesium has specific therapeutic applications, so its choice should be based on each person's characteristics and requirements. If you need guidance, you can write to our team of nutritionists at WhatsApp +56 9 3416 0358 to receive personalized advice and choose the magnesium that best suits your needs.

Cepeda, V., Ródenas-Munar, M., García, S., Bouzas, C., & Tur, J. A. (2025). Unlocking the Power of Magnesium: A Systematic Review and Meta-Analysis Regarding Its Role in Oxidative Stress and Inflammation. Antioxidants, 14(6), 740. https://doi.org/10.3390/antiox14060740

Al Alawi, A. M., Majoni, S. W., & Falhammar, H. (2018). Magnesium and Human Health: Perspectives and Research Directions. International journal of endocrinology, 2018, 9041694. https://doi.org/10.1155/2018/9041694

Pérez González, E., Santos Rodríguez, F., & Coto García, E.. (2009). Homeostasis del magnesio: Etiopatogenia, clínica y tratamiento de la hipomagnesemia. A propósito de un caso. Nefrología (Madrid), 29(6), 518-524. Retrieved January 27, 2026, from http://scielo.isciii.es/scielo.php?script=sci_arttext&pid=S0211-69952009000600004&lng=es&tlng=es.