Magnesium Deficiency: Signs, Symptoms, and Solutions

The Forgotten Mineral

Among essential nutrients, magnesium rarely receives the attention given to calcium, iron, or vitamin D, yet its importance cannot be overstated. This mineral participates in over 300 enzymatic reactions in the human body, influencing everything from energy production and protein synthesis to muscle and nerve function.

Despite its crucial role, magnesium deficiency is remarkably common in developed nations including Australia. Modern agricultural practices have depleted soil magnesium levels, while processed food consumption has replaced magnesium-rich whole foods. Stress, certain medications, and health conditions further deplete this essential mineral.

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Prevalence:

Studies suggest that approximately 50% of Australians do not meet the recommended daily intake of magnesium through diet alone. Subclinical deficiency—insufficient for optimal function but not causing obvious disease—may be even more widespread.

Why Magnesium Matters

Magnesium's roles in the body are diverse and fundamental:

Energy Production

Every cell in your body contains magnesium, and it is essential for ATP (adenosine triphosphate) production—the primary energy currency of cells. Without adequate magnesium, energy production becomes inefficient, potentially contributing to fatigue regardless of adequate sleep and nutrition.

Muscle and Nerve Function

Magnesium regulates muscle contraction by balancing calcium's stimulating effects. It also influences nerve signal transmission throughout the body. Deficiency can manifest as muscle cramps, twitches, and altered nerve sensation.

Bone Health

While calcium receives most attention for bone health, approximately 60% of body magnesium resides in bone tissue. Magnesium influences both bone formation and the regulation of calcium and vitamin D—other nutrients critical for skeletal health.

Blood Sugar Regulation

Magnesium plays a role in insulin secretion and function. Research links low magnesium status with increased risk of type 2 diabetes and metabolic dysfunction.

Heart Health

The heart muscle requires magnesium for proper rhythm and function. Deficiency is associated with increased cardiovascular risk and may contribute to arrhythmias.

Recognising Deficiency Signs

Magnesium deficiency develops gradually, and early signs can be subtle or attributed to other causes:

Early Indicators

Muscle cramps or spasms, particularly in legs at night
Eye twitching
Fatigue despite adequate rest
Difficulty sleeping or staying asleep
Increased stress sensitivity or anxiety
Headaches or migraines
Poor concentration

More Advanced Signs

Numbness or tingling in extremities
Persistent muscle weakness
Heart palpitations or irregular heartbeat
High blood pressure
Worsening PMS symptoms
Increased frequency of headaches

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Testing Challenges:

Standard blood tests measure serum magnesium, which represents only 1% of body stores. Normal serum levels do not rule out deficiency in tissues. Red blood cell magnesium testing provides somewhat better assessment.

Who Is Most at Risk?

Several factors increase magnesium deficiency risk:

Dietary Factors

Those consuming primarily processed foods miss significant dietary magnesium sources. Soft water consumption provides less magnesium than hard water. Alcohol increases magnesium excretion through urine.

Health Conditions

Digestive disorders affecting absorption—including coeliac disease, Crohn's disease, and chronic diarrhoea—impair magnesium uptake. Type 2 diabetes increases urinary magnesium losses. Kidney disease can affect magnesium regulation.

Medications

Several common medications deplete magnesium:

Proton pump inhibitors (reflux medications)
Certain diuretics
Some antibiotics
Oral contraceptives

Life Stages and Lifestyle

Older adults absorb magnesium less efficiently and are more likely to take depleting medications. Athletes and those who sweat heavily lose magnesium through perspiration. Chronic stress increases magnesium requirements while simultaneously depleting stores.

Boosting Magnesium Through Diet

Before considering supplements, optimising dietary magnesium makes sense. Rich food sources include:

Top Dietary Sources

Pumpkin seeds: 150mg per quarter cup
Spinach (cooked): 157mg per cup
Swiss chard (cooked): 150mg per cup
Dark chocolate (70%+): 65mg per 30g
Almonds: 80mg per quarter cup
Avocado: 58mg per medium fruit
Black beans: 120mg per cup
Quinoa: 118mg per cup

Maximising Absorption

Cooking methods affect magnesium content—boiling vegetables in large amounts of water leaches minerals. Steaming or sautéing preserves more nutritional value.

Phytates in some grains and legumes can bind magnesium, reducing absorption. Soaking, sprouting, or fermenting these foods reduces phytate content.

Adequate vitamin D and moderate protein intake support magnesium absorption, while excessive calcium supplementation may interfere with magnesium uptake.

When Supplementation Makes Sense

For those unable to meet needs through diet, or with increased requirements due to health conditions, lifestyle factors, or medications, supplementation can help restore optimal levels.

Choosing the Right Form

Not all magnesium supplements are equivalent. Different forms vary dramatically in absorption and effects:

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Form Guide:

- Magnesium glycinate: High absorption, calming effect, gentle on stomach—excellent for sleep and anxiety - Magnesium citrate: Good absorption, may have mild laxative effect—useful when constipation is also present - Magnesium threonate: Crosses blood-brain barrier—specifically studied for cognitive function - Magnesium oxide: Poorly absorbed, significant laxative effect—primarily useful for constipation, not correcting deficiency

Dosing Considerations

The recommended daily intake for adults is 310-420mg, depending on age and sex. Therapeutic doses for correcting deficiency may be higher temporarily but should not exceed tolerable upper limits without practitioner guidance.

Splitting doses throughout the day enhances absorption compared to taking large amounts at once. Evening dosing may support sleep quality.

What to Expect

Improvements from supplementation often appear within one to two weeks, though full repletion of severely depleted stores may take several months. Many people notice better sleep, reduced muscle tension, and improved mood relatively quickly.

Digestive tolerance varies between individuals and forms. If loose stools occur, reduce dose or try a different form. Magnesium glycinate is typically the most gentle.

A Holistic Approach

While addressing magnesium specifically is important, optimal mineral status depends on a comprehensive approach:

Minimise processed foods and prioritise whole food sources
Manage stress through appropriate techniques
Address underlying health conditions affecting absorption
Review medications with healthcare providers
Ensure adequate but not excessive intake of other minerals

Magnesium does not work in isolation—it interacts with calcium, potassium, sodium, and other nutrients. A balanced approach to nutrition creates conditions for all minerals to function optimally.

For those with persistent symptoms despite dietary improvements and supplementation, working with a healthcare practitioner can help identify underlying issues and develop targeted strategies for restoring magnesium status and overall mineral balance.