Magnesium deficiency

Magnesium is an essential mineral found primarily inside cells and in bone, with only about 1% circulating in the blood. It plays a central role in energy production, protein synthesis, DNA repair, nerve conduction, muscle relaxation, blood pressure regulation, and blood sugar control. It is also required to activate vitamin D and regulate calcium and potassium balance.

Normal serum magnesium ranges from 0.7 to 1.0 mmol/L. Magnesium deficiency is defined as a level below 0.7 mmol/L, though symptoms can occur at borderline levels in people whose intracellular stores are depleted despite normal serum values.

Magnesium deficiency frequently coexists with deficiencies in potassium, calcium, and vitamin D, as magnesium is required for the normal function of all three. Correcting these other deficiencies without first addressing magnesium often produces an incomplete response.

Magnesium deficiency symptoms are wide-ranging and non-specific, making it easy to attribute them to other causes. Common signs include:

• Muscle cramps, twitching, or spasms, particularly in the calves and feet

• Fatigue and low energy despite adequate sleep

• Difficulty sleeping or poor sleep quality

• Anxiety, irritability, or low mood

• Headaches and migraines

• Heart palpitations or irregular heartbeat

• Tingling or numbness in the hands and feet

• Difficulty concentrating or mental fog

• Constipation

• In more severe deficiency: tetany, seizures, and serious cardiac arrhythmias

Magnesium deficiency results from insufficient dietary intake, impaired absorption, or excessive loss. Contributing causes include:

• Inadequate dietary intake is the most common cause. Magnesium is found in leafy green vegetables, nuts, seeds, legumes, and whole grains. Diets low in these foods are consistently deficient in magnesium.

• Alcohol excess is one of the strongest risk factors. Alcohol directly increases renal magnesium excretion and reduces intestinal absorption.

• Chronic stress depletes magnesium through increased cortisol-driven renal excretion.

• Gastrointestinal conditions including coeliac disease, Crohn's disease, and chronic diarrhoea impair magnesium absorption from the small intestine.

• Type 2 diabetes and insulin resistance cause excess magnesium loss through the kidneys, as high glucose increases renal excretion.

• Medications including proton pump inhibitors, diuretics, and certain antibiotics deplete magnesium over time.

• Chronic kidney disease impairs the kidneys' ability to regulate magnesium reabsorption.

• Vitamin D deficiency and magnesium deficiency are closely linked. Magnesium is required to convert vitamin D to its active form, and deficiency in one often accompanies the other.

Magnesium deficiency is detected through blood testing, with supporting markers providing the broader mineral and metabolic context.

Blood tests Elfcare's panel includes magnesium alongside key related markers:

• Serum magnesium: the primary marker; levels below 0.7 mmol/L confirm a deficiency.

• Calcium and albumin-corrected calcium: magnesium deficiency impairs PTH function, reducing calcium levels. Low calcium alongside low magnesium is a clinically important pattern.

• Potassium: frequently depleted alongside magnesium, as magnesium is required for potassium reabsorption in the kidneys.

• 25-OH Vitamin D: magnesium is required to activate vitamin D. Deficiency in both is common and the two should always be assessed together.

• HbA1c and glucose: assess metabolic health. Diabetes and insulin resistance are among the strongest drivers of renal magnesium wasting.

• Creatinine and eGFR assess kidney function, which directly regulates magnesium reabsorption.

• CRP: reflects systemic inflammation. Chronic inflammation increases magnesium demand and contributes to depletion.

• ALT and GGT: assess liver function and alcohol-related damage, as alcohol is a major driver of magnesium deficiency.

• tTG-IgA: screens for coeliac disease, a common cause of magnesium malabsorption.

Why early detection matters

Mild magnesium deficiency is extremely common yet almost universally undetected in standard health assessments. It contributes silently to poor sleep, anxiety, hypertension, insulin resistance, and cardiovascular risk over years. Chronically low magnesium is associated with an increased risk of type 2 diabetes, hypertension, and cardiovascular disease. Correcting deficiency is straightforward and inexpensive, yet the downstream health benefits are substantial. Identifying it early, before it contributes to longer-term metabolic and cardiovascular consequences, is one of the most practical and impactful findings a comprehensive blood test can provide.

How Elfcare can help

Elfcare's blood panel includes serum magnesium alongside calcium, potassium, vitamin D, HbA1c, kidney function, liver function, and coeliac screening. This provides a complete picture of magnesium status and the metabolic and nutritional context most likely driving deficiency.

Measuring magnesium alongside calcium, potassium, and vitamin D is particularly important because these minerals are functionally interdependent. Identifying magnesium deficiency often explains why other mineral and vitamin corrections have not produced the expected response.

If our blood tests identify magnesium deficiency or related mineral imbalances, we take care of further diagnostics or refer you to the appropriate specialist.