Red cell magnesium blood test in Chiswick

What the test measures

Magnesium is involved in hundreds of reactions in the body, including energy production, muscle and nerve function, heart rhythm and bone health. It is found in leafy greens, nuts, seeds, wholegrains and beans. Most magnesium is stored in bone and inside cells, with only around one per cent in the blood.

The routine NHS test measures serum magnesium, which can stay normal even when stores are lower. Red cell magnesium measures magnesium inside the red blood cells and is used by some clinicians as a complementary marker. It is not a routine NHS test and there is less agreement about how it should be interpreted, so it is best read alongside serum magnesium, potassium and calcium.

The price includes the sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result, and a GP feedback report on request.

Who it is for

• You have muscle cramps, twitching or tiredness and want to look at possible nutritional factors.
• You take proton pump inhibitors such as omeprazole long term, or diuretics, which can lower magnesium.
• You have a digestive condition, such as Crohn disease or coeliac disease, that may reduce absorption.
• You drink alcohol regularly and would like to check your mineral status.
• You have a normal serum magnesium result but your practitioner would like an additional measure.

Understanding your result

Your report shows your red cell magnesium level and the laboratory reference range. A lower result may suggest reduced magnesium stores, which can be linked to diet, medicines, alcohol or absorption problems. A raised level is uncommon and may reflect supplements or reduced kidney clearance.

Because this marker is less established than serum magnesium, your practitioner will interpret it with your symptoms and other results. An out-of-range value opens a conversation; it is not a diagnosis. Palpitations or severe muscle weakness should be assessed by your GP.

Preparing for your test

There is no need to fast. Please tell us about any magnesium supplements, antacids, laxatives, diuretics or acid-reducing medicines you take, as these can affect magnesium. Further instructions, if any, are given when you book.

For a broader view of minerals and vitamins, Nutritional and Digestive Health looks at several diet-related markers, and our kidney function tests help show how minerals are cleared. Browse every blood test and price in Chiswick.

Questions

How much is a red cell magnesium test in Chiswick?

The Red Cell Magnesium test costs £159. It includes the blood sample at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result, and a GP feedback report on request.

Is red cell magnesium better than serum magnesium?

They measure different things. Serum magnesium is the standard NHS test. Red cell magnesium looks inside cells and can add detail, but it is less well established.

Can medicines lower my magnesium?

Yes. Long-term proton pump inhibitors and some diuretics are well-known causes of low magnesium. Do not stop prescribed medicines without speaking to your GP.

Should I take magnesium supplements if my level is low?

Your practitioner will talk through diet and supplement options. If you have kidney disease, check with your GP before taking magnesium.