Insight into your magnesium level.
Magnesium is a mineral that plays a role in more than 300 enzymatic processes, including muscle and nerve function. A test gives insight into the magnesium level in your blood.
Also known as: serum magnesium, Mg
Personal assessment by our BIG-registered doctors
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Blood draw
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Receive your report
Securely, typically within 2 working days from our physicians
Background
What is magnesium?
Magnesium is the fourth most abundant mineral in the body and plays a role in more than 300 enzymatic processes, from energy production and protein synthesis to muscle and nerve function and blood pressure regulation. Approximately 60% of the magnesium in the body is stored in the bones, 39% in soft tissues and muscles, and only 1% in the blood.
Because the vast majority of magnesium is intracellular (inside the cells), a serum magnesium measurement (such as this test) cannot always reliably rule out a deficiency. For a more sensitive measurement of cellular status, the "intracellular magnesium" or "RBC magnesium" test exists, which we do not currently offer. For most questions, however, the standard serum measurement provides an initial indication.
In brief
300+ enzymes
Cofactor in countless processes
Muscle function
Important for contraction and relaxation
Nerve function
Regulates signal conduction
Bone health
60% of magnesium is in bones
This marker is also included in
Testing several values in a single draw takes one blood collection and gives a more complete picture. The choice is yours.
Common reasons to test
When can insight into your Magnesium be valuable?
Below are some situations in which measuring Magnesium can provide insight.
Insight into your status
A test gives a snapshot of your serum magnesium level.
For athletes
Intensive exercise increases the requirement for magnesium; testing can be part of performance monitoring.
With questions about muscle function
Magnesium plays a role in muscle relaxation. Complaints of cramps are often associated with magnesium status.
With questions about sleep
Magnesium is sometimes associated with sleep quality; a test gives insight into whether the blood level is sufficient.
Tracking the effect of supplementation
Those taking magnesium supplements can test whether this has influenced their serum level.
With long-term medication use
Certain medications (such as diuretics and long-term proton pump inhibitor use) can affect magnesium status.
What your result means
Magnesium too low or too high: what does your result mean?
Magnesium is measured in millimoles per litre (mmol/L). Important: serum magnesium does not always reflect the magnesium status within the cells, a normal blood level does not 100% rule out a functional deficiency. Reference values differ between laboratories and methods; the values of the laboratory that performs your test are leading.
A low value
Low serum magnesium generally indicates a clear deficiency. Possible causes include insufficient intake, increased loss (for example due to certain medications or prolonged diarrhoea), or reduced absorption from the gut. Supplementation through diet or supplements is a common approach.
A normal value
Serum magnesium within the reference range gives a reassuring picture for this marker. Bear in mind that this is a snapshot of blood magnesium, the vast majority of magnesium is located within the cells, and a functional deficiency at cellular level could theoretically still exist even with a normal serum value.
An elevated value
Elevated serum magnesium is rare and is sometimes seen with reduced kidney function or with excess intake of magnesium-containing medications or supplements. For significantly elevated values, our doctor provides explanation and context.
How we interpret your result
Our doctors interpret your magnesium level against the reference ranges and your personal context, lifestyle, medication use, and any known conditions.
Related tests
Often combined with Magnesium.
A single marker gives one perspective. For a broader picture you can combine Magnesium with a theme package or related markers.
+ €29 blood draw fee per orderFree from €225
Frequently asked questions
Everything you want to know
Do I need to fast for a magnesium test?
No, you do not need to fast for a magnesium measurement.
What is the difference between serum magnesium and intracellular magnesium?
Serum magnesium measures the magnesium in the blood plasma, only 1% of total body magnesium. Intracellular magnesium measures the mineral inside the red blood cells and is more sensitive for detecting a functional deficiency. We measure standard serum magnesium.
Which form of magnesium supplement is commonly used?
Widely used forms include magnesium citrate and magnesium bisglycinate (chelated). Magnesium oxide is cheaper but less well absorbed. The choice depends on your goal and preference.
Which foods contain a lot of magnesium?
Good sources of magnesium include leafy green vegetables (spinach, chard), nuts and seeds (especially pumpkin seeds and almonds), legumes, wholegrains, dark chocolate, and avocado.
How do I know if I am getting too much magnesium?
With healthy kidney function, excess magnesium is excreted in the urine. However, excessive supplementation can cause diarrhoea, often the first signal to reconsider the dose.
Does my medication affect my magnesium level?
Yes, certain medications (especially diuretics, long-term use of proton pump inhibitors, and certain antibiotics) can affect magnesium status.
How often should I measure magnesium?
A single measurement is sufficient for initial insight. With active supplementation or as follow-up to a previously low value, re-testing after a few months is common.
What do I do with my result?
You will receive a PDF report with your value and explanation. What you do with it, such as discussing it with your GP or adjusting your diet, remains entirely your choice.
In the Health Guide
Read more about this value
Ready for insight into your magnesium level?
You receive your magnesium level including personal explanation from a doctor, typically within 2 working days. No referral required.
Order Magnesium →Want to test multiple markers at once?
Combine Magnesium with other markers via Bloodworks Select. The blood draw and collection fee is charged once per order, and is waived from €225.
45,-
+ €29 blood draw fee+ €29 blood draw fee per order