Hi all, I received an abnormally high (3.0 mg/DL) level of magnesium on a blood test with my PCP. Reference range is 1.5-2.5 mg/DL. I do not take magnesium supplements. I'd been concerned I was deficient. My doctor told me not to take supplements. An additional test, which measures magnesium inside RBCs, and that I took with an alternative health practitioner, showed that I was deficient. Now, I presume the test with my PCP measured serum levels, while the test by my alternative doctor measured cell levels. Anyone have any idea what could explain high serum concentrations of magnesium, but low intracellular concentrations?