By Emmett Hughes, DC, MS
American Chiropractic Association
Magnesium is the second most abundant intracellular cation, with potassium the most abundant. Sixty percent of the body’s magnesium is found in bone, 25 percent in muscle and the remainder in soft tissue and fluids, especially gastric juice. The majority of magnesium in muscle is found in the mitochondria, where it is thought to play a role in permeability of the outer membrane.
Dietary intake of magnesium has gone down dramatically over the past 100 years. It is estimated that 68 to 80 percent of Americans are magnesium deficient.2-4 In places where water is harder, levels of magnesium are higher, and the incidence of coronary artery disease is lower. It appears, however, that 8 million deaths from sudden cardiac failure occurred in the United States between 1940 and 1994 because of magnesium deficiency.
Testing and Absorption
Serum levels are a poor indicator of magnesium status. Heart muscle levels are almost 20 times higher than serum levels, so measuring white blood cell levels is a more sensitive test. The best test is ionic magnesium measurement or elemental X-ray analysis using a buccal smear. However, none of these methods are definitive.