ill patients in the hospital. Abuse of antacids and
laxatives containing magnesium hydroxide can also
result in hypermagnesemia. Symptoms of hypermag-
nesemia (in increasing severity )include nausea, vomit-
ing, lightheadedness, muscle weakness, loss of deep
tendon reflexes, low blood pressure, irregular heart
rhythms, coma, and death.
Hypomagnesemia, or low levels of magnesium are
estimated to occur in about 2 of the American popu-
lation, in 1,020 of hospitalized patients, and in up to 60
of patients in intensive care. Anywhere between 30 and
80 of people with alcoholism have hypomagnesemia,
as do about one-fourth of people with diabetes.
Magnesium deficiency can be caused either by
insufficient intake or excessive excretion of magne-
sium. Causes of insufficient intake include digestive
disorders that interfere with the absorption of magne-
sium (e.g. Crohns disease,celiac disease, inflamma-
tory bowel syndrome), malnutrition with a limited diet
of green vegetables, alcoholism (alcohol is substituted
for food), and anorexia nervosa(self-starvation).
Some causes of excessive excretion of magnesium
include kidney failure, diabetes, use of some diuretic
drugs, and some hormone disorders of the parathy-
roid gland.Precautions
The kidneys are the main regulator of magnesium.
People with kidney disease should not take magne-
sium supplements.
Pregnant women should discuss their magnesium
needs with their healthcare provider. Many pregnant
women have low levels of magnesium but should use
supplements only under medical supervision. Low
magnesium levels are thought to contribute to pre-
eclampsia and eclampsia and possibly to increase the
risk of early labor.
People undergoing surgery should tell their anes-
thesiologist if they are taking magnesium supplements,
antacids, or laxatives because magnesium increases the
muscle-relaxing effects of certain anesthetics.Interactions
Certain drugs and conditions can cause an exces-
sive loss of magnesium. These include:
cisplatin, a drug used in cancer treatment
diuretics (water pills)
fluoride poisoning
Certain drugs may be less effective when taken
with magnesium supplements. These include some anti-biotics, and digoxin, a heart medication.Ironmay be
absorbed more poorly in the presence of magnesium.
Some minerals decrease the absorption of magne-
sium. These include calcium,manganese, and phos-
phate. Boron appears to increase magnesium levels.Complications
No complications are expected from magnesium
obtained from food and water. Potential complica-
tions related to excess use of magnesium supplements
or from inadequate levels of magnesium are discussed
above.Parental concerns
The safety of magnesium supplements in children
has not been investigated. Breastfeeding women should
avoid magnesium supplements and children should be
encouraged to meet their magnesium requirements by
eating a healthy diet high in green vegetables and whole
grains and low in fat.Resources
BOOKS
Cohen, Jay S.The Magnesium Solution for Migraine Head-
aches.Garden City Park, NY: Square One, 2004.
Dean, Carolyn.The Magnesium Miracle: Discover the
Essential Nutrient That Will Lower the Risk of Heart
Disease, Prevent Stroke and Obesity, Treat Diabetes,
and Improve Mood and Memory.New York: Ballantine
Books, 2007.
Fragakis, Allison.& The Health Professionals Guide to
Popular Dietary Supplements.Chicago: American Die-
tetic Association, 2003.
Lieberman, Shari and Nancy Bruning.The Real Vitamin and
Mineral Book: The Definitive Guide to Designing Your
Personal Supplement Program,4th ed. New York:
Avery, 2007.
Pressman, Alan H. and Sheila Buff.The Complete Idiots
Guide to Vitamins and Minerals,3rd ed. Indianapolis,
IN: Alpha Books, 2007.
Seelig, Mildred S. and Andrea Rosanoff.The Magnesium
Factor.New York: Avery, 2003.
PERIODICALS
He, Ka, Liu Kiang, Martha L. Daviglus et al. ‘‘Magnesium
Intake and Incidence of Metabolic Syndrome Among
Young Adults.’’Circulation113, no. 13 (April 4,
2006):1675-1682. http://circ.ahajournals.org/cgi/content
/abstract/113/13/1675
van Dam, Rob M., Frank B. Hu, Lynn Rosenberg, et Al.
‘‘Dietary Calcium and Magnesium, Major Food Sour-
ces, and Risk of Type 2 Diabetes in U.S. Black
Women.’’Diabetes Care29, no 10 (2006):2238-43.
http://care.diabetesjournals.org/cgi/content/abstract/
29/10/2238:Magnesium