Magnesium is an important macro-mineral in the body, stored mostly in the bones and skeletal and cardiac muscles. It is necessary for more than 300 essential biochemical reactions, including the proper function of cell membranes, DNA replication, blood sugar balance, healthy muscle and nerve function, protein synthesis, carbohydrate metabolism to name but a few.  It is not surprising then that magnesium plays a significant role in the healthy functioning of all body systems.

Magnesium also has important roles with calcium, potassium (regulating the sodium/potassium pump), phosphorus (energy production and ATP), copper, zinc and vitamin D metabolism in the body.

Magnesium is absorbed via the small intestine and the rate of absorption adjusts relevant to the level of dietary intake.  When dietary magnesium is high the absorption rate is lower, increasing excretion via the kidneys, and conversely, when dietary magnesium is low, absorption efficiency increases to compensate.

Only one percent of our magnesium is found in the blood, so a deficiency is unlikely to show up in the standard blood serum test (Measuring either intracellular magnesium or free ionic cellular magnesium are the only accurate lab tests for magnesium deficiency).

Can I get enough magnesium from my regular dietary intake?

The answer is yes – with a balanced, healthy and nutrient-rich diet.

Magnesium deficiency has become common among populations with a western-style lifestyle and diet.

To correct a long-term magnesium deficiency it might be beneficial to take a mineral supplement for a while, while you attend to the cause(s). If the cause is a dietary imbalance the good news is there are plenty of magnesium-rich foods to include in your regular meals for a more balanced mineral intake.

Green leafy vegetables, artichokes, avocados, sweetcorn, nuts, pumpkin seeds, whole grains, chickpeas (and other legumes), cocoa products, sundried tomatoes, fish and other seafood, molasses, dried fruit and many more foods contain high amounts of magnesium.

The main cause of magnesium deficiency is not from low magnesium food intake, but rather from other factors that limit its availability in the body, interfering with absorption or increasing excretion of magnesium.

The calcium:magnesium ratio

One of the most important relationships for magnesium balance is the ratio between calcium and magnesium.  Our ancestors ate a diet that provided calcium and magnesium in a ratio of 1.3:1.  No greater than a 2:1 ratio is needed by the body for optimal functioning.  Modern dietary habits, with high dairy product intake, have pushed this vital calcium to magnesium ratio to a disproportionate 5:1.  This just highlights that it is good practice to have a balanced diet of calcium and magnesium rich foods.

Risk factors for magnesium imbalances

  • Chronic stress, sleep problems, excessive exercise all increase the stress hormone cortisol, which in turn depletes magnesium
  • Dietary: a diet high in salt, meat, fat, dairy foods, refined flour and sugar. Regular or high intake of coffee, alcohol and soft drinks can also lead to magnesium imbalance.
  • Profused sweating
  • Heavy menstruations.
  • Conditions which affect magnesium absorption and metabolism like, for example, kidney imbalance, a microbial imbalance in the gut as well as improper gut function, mineral imbalances, blood sugar imbalances or thyroid dysfunction.
  • Certain medications may interfere with magnesium balance. It is always good to check with the health professional.
  • During pregnancy and breastfeeding magnesium needs are increased.

 Healthy kidney function primarily governs how much magnesium the body conserves.   Up to 95% of magnesium are reabsorbed prior to excretion via the urine.  Factors that promote higher excretion rates of magnesium are diuretics (as in coffee or alcohol or medications), heart regulating medication, high sodium and calcium intake, excessive sugar consumption and overactive adrenal hormone (stress hormones) production.

Signs of magnesium deficiency may include:

  • Muscular and nerve imbalances
  • Irregular heart beats
  • fatigue, low energy
  • sleep problems, especially having difficulties maintaining sleep
  • mood imbalances
  • poor memory and concentration
  • imbalanced bowel movements
  • increased pain sensations

Maintaining adequate magnesium levels throughout life will help to prevent or give support in many chronic conditions and assist wellbeing including energy and mood.

Which form of supplement is most effective?

Magnesium supplements come in many varieties.  Oral supplements come in tablets, capsules or as a powder. Magnesium is available either as salts or chelated to an amino acid because the body cannot absorb pure magnesium.

Different forms of magnesium may be used according to different needs of the individual:

  • Magnesium oxide to help normal bowel function and digestion
  • Magnesium citrate to help mineral balance and healthy pH
  • Magnesium glycinate for a very well absorbed form of magnesium and for a soothed nervous system.
  • Magnesium malate for healthy muscular function and to support energy.
  • Magnasium orotate and taurate to support heart health and balanced cardiovascular function.
  • Tissue salts provide magnesium in form of magnesium phosphate

Transdermal delivery (through the skin) is another way of absorbing magnesium although taking magnesium supplements orally will assist with a faster response.

Some forms of magnesium, such as magnesium hydroxide, magnesium oxide, magnesium carbonate, magnesium chloride and magnesium sulphate (Epsom salts) are more likely to cause diarrhoea.

Vitamin B6 (pyridoxine) increases magnesium uptake at a cellular level, so it’s important to have adequate B vitamin intake to optimise your magnesium absorption.  All forms of oral magnesium supplements are better absorbed when taken with a meal.  Factors affecting absorption can include dietary toxins, medical drugs, intestinal inflammation or infection, cell membrane health, kidney health, obesity and some genetic conditions.

What is the recommended daily magnesium intake?

310 to 420 mg (differing according to age, sex, weight and other variables) is the recommended daily intake for adults from all sources – that is the combined food and supplement intake.  Teenagers after puberty require the same intake as adults, and more during growth spurts.  Pre-teens need two thirds of the adult intake and younger children a third to a half.

What is adequate supplementation?

In general, around 200 mg per day from a supplement with good bioavailability is an adequate amount to restore and maintain healthy function. Spreading your magnesium dosage into two or three daily doses helps increase the absorption rate and reduce the risk of diarrhoea occurring from the unabsorbed excess being excreted.

It can take several months of ongoing supplementation to restore your body’s magnesium reserves, so look for a gradual improvement in symptoms rather than immediate relief.

For most people, magnesium supplements cause no adverse effect.

Are there any contraindications or adverse effects reported?

If you have seriously impaired kidney function, magnesium supplements may lead to dangerously high plasma concentrations of magnesium, and may therefore be contraindicated.  Consult your health professional.