Why is my serum magnesium normal but I have symptoms of hypomagnesemia ?
Approximately 55% of the total body magnesium is in the skeleton and the remainder is intracellular (inside the cell), where it is the second most prevalent cation. Extracellular (Outside the cell) magnesium accounts for about 1% of the total body magnesium content. When your doctor does a serum magnesium level this is what they are checking (The extracellular level). Which is why we say you can still be hypomagnesemic (Low magnesium) despite a normal serum magnesium level. They are only checking 1% of your total magnesium content in your body when they do a serum magnesium level. One test that can be easily done is a red blood cell magnesium level (RBCMg). This will tell your doctor what is happening inside the cell where the majority of your magnesium is stored. This test also does not adequately reflect total body magnesium status in health and disease. Another test that can be done is a Magnesium Load Test. This test is done if your physician thinks you may be losing the magnesium
