A few things to know…
“Salt lowers cellular magnesium.
Glucose lowers cellular magnesium.
Pregnancy lowers cellular magnesium (especially if pregnancy is complicated by diabetes).
Aging lowers cellular magnesium.
Insulin temporarily raises blood magnesium, but it causes increased magnesium loss through the urine, ultimately leading to a lowering of cellular magnesium and increase in cellular calcium.” From The Magnesium Factor – Mildred Seelig, M.D., Andrea Rosanoff, Ph.D.
Dr. Sarah Myhill recommends magnesium be taken by injection when the body is severely depleted, which is usually the case with CFS/M.E. and, if injection is not available, via nebuliser (this is my new planned approach!). Typical blood tests might not necessarily reveal whether your body is severely depleted.
Another great source for magnesium? There’s also the great magnesium oil alternatives putting it directly on the skin and into the system via absorption.