How To Test for Magnesium Deficiency

How To Test For Magnesium Deficiency

Since magnesium is found inside our bones, muscles, and brain tissue, it can be difficult to properly determine the amount of magnesium in our bodies. As a result, multiple tests have been developed to estimate our total magnesium levels.

There are currently four types of magnesium tests that our customers ask about:

  • RBC
  • Serum
  • Ionic
  • EXA Test

All are blood tests except for EXA Test (which uses mouth tissue).

RBC Magnesium Test - RECOMMENDED

Similar to the serum magnesium test, the RBC magnesium test is a blood test.

However, unlike the serum magnesium test, the RBC magnesium test checks the magnesium levels inside your actual cells. In particular, it provides a look at the amount of magnesium in the red blood cells (hence RBC).

In general, the RBC test is considered more accurate than the serum test. Why? Because when you are low in magnesium your body takes it from cells for use elsewhere. So if these red blood cells are lacking magnesium then you have an early indicator of deficiency.

This makes it a more accurate test, but since it is more complex than the serum test it tends to be less common.

Serum Magnesium Test

The serum magnesium test is the most common test for magnesium deficiency. As the name implies, it checks the magnesium levels in your blood serum.

The test is commonly done in doctor’s offices or labs. Since this is the most common method, it is the most likely test that a doctor will recommend if she suspects a patient is suffering from magnesium deficiency.

What is serum? It is the plasma, antibodies, and non-clotting proteins that are found in your blood. It basically accounts for everything in your blood except anything that is:

  • a blood cell
  • involved in clotting

The problem with the serum test is that most of the magnesium in our bodies exist in our cells: serum contains less than 1% of our total magnesium.

So it is quite possible for the magnesium levels elsewhere in your body to be low but have the serum test come back normal.

Ionized Magnesium Test

The least common blood test is the ionized magnesium test. It was developed by two professors, Bella and Burton Altura, at SUNY in New York where they do their testing using a special machine that isolates the magnesium ions.

The ionized test is the most accurate of the blood tests because it tests the actual magnesium ions in your body. Being able to isolate and test the active magnesium ions allows doctors to get a more specific reading of our overall magnesium levels.

Although it is more accurate than the serum and RBC tests, it is difficult for the average person to get tested this way simply because it is only available in a few select locations.

EXA Test

The EXA Test is a method of determining magnesium levels without taking a blood sample.

Instead of a blood draw, it is more like a cheek swab: tissue is scraped from the mouthand then tested for magnesium content.

Since most of your magnesium is found in soft tissue, analyzing tissue from the mouth should provide a much better idea of the magnesium content of your body.

However, similar to the ionized magnesium test, the EXA Test requires specific testing materials. As a result it may be difficult to find a doctor or lab that can perform the test and analyze the results.

How To Get Tested

While we've provided lots of information for you about testing, we want to reinforce that Dr. Carolyn Dean recommends you get the RBC magnesium test since it is most accurate for identifying and monitoring magnesium deficiency symptoms. You can ask your doctor or you can also order the magnesium RBC tests online:

Your blood is drawn locally by a medical professional at one of the many official blood labs they partner with. Once it is analyzed, they will send you the results of the tests you ask for.

You place the order online or by phone, go for the blood draw at your convenience, and then you can either get your results online or via mail (or both).

As usual, the blood tests have very few risks associated with them. The main concerns would be excessive bleeding or infection at the site where the blood is drawn, though these risks can usually be avoided by following proper sterilization and blood draw procedures.

And, as always, it is important to make sure whoever is administering the test is aware of any medications you are on so this may be taken into account when analyzing the results of your test.

PLEASE NOTE! For the best result with any mineral testing, fast your regular supplementation for 12-24 hours prior to the test.