Vitamins and MineralsMagnesium



June 25, 2020

Vitamins and Minerals

What is Magnesium?

Magnesium is an essential mineral that is vital for energy production, muscle contraction, nerve function, and bone mineralization.

Magnesium acquired from the diet is absorbed by our bodies from the small intestine and colon, and then stored in the bones, cells and tissues. Excess magnesium leaves the body via urine and stool. Magnesium is found in small amounts in a wide variety of foods, especially in green vegetables such as spinach, as well as in cereals and nuts. Foods containing fiber also tend to be good sources of magnesium.

For more information about magnesium and pregnancy specifically, click here.

Why is this analysis important?

The increased intake of processed food with a low magnesium content as part of the fast-paced modern lifestyle has led to suboptimal magnesium status in many people. Though mild magnesium deficiency usually does not cause any symptoms. Prolonged and more severe abnormalities in magnesium levels can result in vague symptoms such as fatigue, loss of appetite, depression, muscle twitches, cramps and tremors. The symptoms of high and low magnesium levels can be very similar and a blood test is often needed to tell the difference.

Low magnesium levels in the blood have also been associated with disease such as kidney failure, alcoholism, type 2 diabetes, high blood pressure, osteoporosis, migraine headache and asthma.

In short, it is useful to analyse magnesium levels in the blood to:

  • Detect magnesium deficiencies

  • Detect high magnesium levels


The reference range for magnesium levels in the blood can be different depending on the laboratory and technique used. Doctors usually also take into account a number of factors when evaluating magnesium values.

High magnesium levels in the blood may be associated with:

  • Excessive use of antacids containing magnesium hydroxide or magnesium carbonate.

  • Kidney failure

  • Lithium treatment

  • Endocrine disorders:

  • - Underactive thyroid (hypothyroidism)

  • - Addison’s disease

Low magnesium levels in the blood may be associated with:

  • Insufficient magnesium intake

  • Excessive alcohol consumption

  • Gastrointestinal losses

  • - Diarrhea or vomiting

  • - Intestinal malabsorption such as inflammatory bowel disease (such as Crohn's disease or Ulcerative colitis) or gastric bypass surgeries

  • - Acute or chronic pancreatitis

  • - Prolonged use of Proton Pump Inhibitors (for example: Omeprazole)

  • Kidney losses

  • - Use of Loop diuretics (for example: Furosemide) or Thiazides (for example: Hydrochlorothiazide)

  • - Certain kidney diseases

  • Endocrine disorders:

  • - Poorly controlled diabetes

  • - Overactive parathyroid (hyperparathyroidism)

  • - Overactive thyroid (hyperthyroidism)

  • Oversecretion of the hormone aldosterone (hyperaldosteronism)

  • Use of certain medication:

  • - Such as Aminoglycosides, Amphotericin B, Cisplatin, Calcineurin Inhibitors (for example: Tacrolimus) or Digoxin

Other Considerations

Normally, only about 1% of all magnesium is found in the blood and for this reason it is difficult to know the body's magnesium content exactly only from a blood test. However, a blood magnesium test continues to be useful for evaluating the state of magnesium in the body.It is common to carry out a magnesium test together with the analysis of Calcium, Potassium, Phosphate or Chlorine because the alterations of these salts and minerals electrolytes are often closely related.

Tests that include this marker


Rosanoff A, Weaver CM, Rude RK. Suboptimal magnesium status in the United States: are the health consequences underestimated?. Nutr Rev. 2012;70(3):153‐164.

Swaminathan R. Magnesium Metabolism and its Disorders. Clin Biochem Rev. 2003 May; 24(2): 47–66.

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