nerve impulse transmission
conversion of nutrients into energy
movement of ions across cell membranes
regulation of blood glucose (sugar) levels
regulation of blood pressure
protecting the body against cardiovascular diseaseDescriptionMagnesium is in chlorophyll, the pigment that
makes plants green. Humans absorb magnesium
from food as it passes through the small intestine.
The kidneys normally regulate how much magnesium
is in the blood, and any excess magnesium is excreted
in urine. Magnesium levels can be measured with a
blood test.
When magnesium dissolves in body fluids, it
becomes an electrolyte. Electrolytes are ions that
have an electric charge. Magnesium is a cation, or
positively charged ion, with an electric charge of +2,
meaning it has lost two of its negatively charged elec-
tions. Other important electrolytes in the body are
sodium(Na+), potassium (K+),calcium(Ca 2+),
and the negatively charged ions chloride (Cl-), phos-
phate (HPO 4 2-), bicarbonate (HCO 3 -), and Sulfate
(SO 4 2-). Multiple electrolytes are involved in most
metabolic reactions. These electrolytes are not evenlydistributed within the body, and their electric charge
and uneven distribution are what allow many chemical
reactions to occur. About 50-60% of the 25 grams of
magnesium in an adult’s body, is in the bones. About
25% is in muscle cells, 6–7% in other cells, and less
than 1% outside cells (e.g. in extracellular fluid or in
blood serum).
Magnesium is involved in many reactions. One of
the most important is in synthesizing adenosine tri-
phosphate (ATP), the molecule that supplies most of
the energy to drive cellularmetabolism. Magnesium is
also required to create new DNA, Ribonucleic acid
(RNA), and proteins. The electrical charge of the
magnesium ion is important in regulating the trans-
mission of nerve impulses, muscle contraction, and the
movement of nutrients and other electrolytes in and
out of cells. Magnesium also has an effect on the way
calcium is deposited in bones. It makes bone structur-
ally more dense and stronger.Normal magnesium requirements
The United States Institute of Medicine (IOM) of
the National Academy of Sciences has developed val-
ues calledDietary Reference Intakes(DRIs) for many
vitaminsandminerals. The DRIs consist of three sets
of numbers. The Recommended Dietary Allowance
(RDA) defines the average daily amount of theKEY TERMS
Dietary supplement—A product, such as a vitamin,
mineral, herb, amino acid, or enzyme, that is
intended to be consumed in addition to an individ-
uals diet with the expectation that it will improve
health
Diuretic—A substance that removes water from the
body by increasing urine production
Electrolyte—Ions in the body that participate in met-
abolic reactions. The major human electrolytes are
sodium (Na+), potassium (K+), calcium (Ca 2+), mag-
nesium (Mg2+), chloride (Cl-), phosphate (HPO 4 2-),
bicarbonate (HCO 3 -), and sulfate (SO 4 2-).
Glucose—A simple sugar that results from the break-
down of carbohydrates. Glucose circulates in the
blood and is the main source of energy for the
body.
Ion—An atom or molecule that has an electric
charge. In the body ions are collectively referred to
as electrolytes.Mineral—An inorganic substance found in the earth
that is necessary in small quantities for the body to
maintain health. Examples: zinc, copper, iron.
Osteoporosis—A condition found in older individu-
als in which bones decrease in density and become
fragile and more likely to break. It can be caused by
lack of vitamin D and/or calcium in the diet.
Ribonucleic acid (RNA)—A molecule that helps
decode genetic information (DNA) and is necessary
for protein synthesis
Serum—The clear fluid part of the blood that remains
after clotting. Serum contains no blood cells or clot-
ting proteins, but does contain electrolytes.
Triglycerides—A type of fat found in the blood. High
levels of triglycerides can increase the risk of coro-
nary artery disease
Type 2 diabetes—Sometimes called adult-onset dia-
betes, this disease prevents the body from properly
using glucose (sugar).Magnesium