Magnesium is an important mineral that is involved in a number of metabolic events. It takes part in energy production, muscle and nerve function, and metabolism of bones. Approximately one-half of the magnesium present in the body is inside cells, and one-half is bound to the bones together with potassium and phosphate. Only approximately 1% of it is free in the blood.
We get magnesium from almost all foods, but the biggest concentrations are found in grain products, coffee and mineral water, vegetables such as potatoes, berries and fruit, and dairy products.
Excess intake of magnesium from food is not a concern; the kidneys regulate the body’s magnesium levels by filtering excessive magnesium into urine.
When should magnesium be measured?
Magnesium is often measured when examining magnesium levels in the blood, especially in connection with diseases of the kidneys.
If you exhibit the following symptoms, having your magnesium level checked might be in order. They can be a sign of too low magnesium levels in the body.
- Muscle twitch, shivers, convulsions
Magnesium is rarely found in excessive amounts in the body, because the body regulates the level of magnesium to a suitable level itself. However, it can be seen in connection with gut malabsorption (coeliac disease).
What does a magnesium test measure?
The test measures the level of magnesium in the blood. Only approximately 1% of the body’s magnesium is free in the blood.
The result indicates whether there is enough magnesium in the blood or whether there is any magnesium deficiency.
How to interpret the magnesium test result?
Normally, the result is:
Reference values: 0.71–0.94 mmol/l
Magnesium deficiency is challenging to diagnose. Deficiency of magnesium inside the body’s cells cannot always be seen in the blood. A decreased magnesium level in the blood indicates magnesium deficiency.
In connection with low magnesium levels, it is recommended to also have potassium (S-K) and calcium (S-Ca) levels tested, because they are often associated with magnesium deficiency.
According to Finnish recommendations, the daily intake of magnesium should be 350 mg for men and 280 mg for women.
What can cause elevated magnesium levels?
Excessive amounts of magnesium in the body are very rare. Magnesium from food and magnesium from magnesium supplements do not accumulate in the body in excessive amounts.
Magnesium supplements can increase the blood magnesium levels to a harmful degree in those with kidney failure and very old people. Elevated values can also been seen in situations in which intravenous feeding has been used.
What can cause decreased magnesium values?
Too low a magnesium level in the body is possible, but rare in healthy individuals.
Usually, decreased magnesium levels can emerge in connection with gut malabsorption, such as coeliac disease. Diarrhoea and vomiting can also impair the absorption of magnesium.
In rare cases, long-term continuous use of antacids (over 3 months) can also cause magnesium deficiency.
Magnesium is excreted from the body with urine during the use of diuretics or as a result of long-term alcohol use and in those with diabetes, when the amounts of urine increase due to abnormal sugar balance.
Magnesium is also low in liver cirrhosis and hypoparathyroidism (underactive parathyroid) and when too much aldosterone is secreted from the adrenal gland in connection with diseases.
The most typical additional magnesium tests:
- Calcium is critical for all cells of the body (2013 S-Ca, 2019 fS-Ca-Ion, 6032 S-Ca-Albk)
- Potassium is one of the most important minerals in the blood (2001 S-K)
- Sodium is the most important salt in bodily fluids (2382 S-Na)
SYNLAB test list: Magnesium (2303 S-Mg) https://www2.synlab.fi/laboratoriokasikirja/tutkimuskuvaukset/magnesium/
[Rivityskohta]Terveyskirjasto health library: Magnesium https://www.terveyskirjasto.fi/terveyskirjasto/tk.koti?p_artikkeli=dlk00818&p_hakusana=magnesium
Terveyskirjasto health library: Magnesiumin vähyys yhteydessä sydänriskeihin https://www.duodecim.fi/2020/01/15/magnesiumin-vahyys-yhteydessa-sydanriskeihin/
Fasting is not required
This examination does not require fasting