If you’ve recently had a blood test, you might assume it would show a magnesium deficiency. But only 1 percent of magnesium in your body is distributed in your blood, making a simple sample of magnesium from a serum magnesium blood test not very useful.
Most magnesium is stored in your bones and organs, where it is used for many biological functions. Yet, it’s quite possible to be deficient and not know it, which is why magnesium deficiency has been dubbed the “invisible deficiency.”
By some estimates, up to 80 percent of Americans are not getting enough magnesium and may be deficient. Other research shows only about 25 percent of US adults are getting the recommended daily amount of 310 to 320 milligrams (mg) for women and 400 to 420 for men.2
Even more concerning, consuming even this amount is “just enough to ward off outright deficiency,” according to Dr. Carolyn Dean, a medical and naturopathic doctor.