v57, Better Nutrition for Today's Living, March
A recent survey conducted by The Gallup Organization
has found that 72 percent of adult Americans are
falling short of the Recommended Dietary Allowance
The survey further revealed that 55 percent of
all adults are consuming three-quarters or less
of the RDA, while 30 percent are eating less than
half the required amount of the mineral.
The survey also reported that magnesium consumption
decreases as we age, with 79 percent of adults 55
and over reportedly eating below the RDA for magnesium,
and 66 percent are getting less than three-quarters
of their allowamce from food.
Food sources of magnesium include wheat germ, wheat
bran, brewer's yeast, nuts, peanuts, soybeans, whole-grain
oats and barley, millet, corn and beet greens.
For males 19 and over, the RDA for magnesium is
350 mg/day. For females 19 and over, RDA is 280
mg/day. The RDA for pregnant women is 320 mg/day;
and for breast-feeding women, 355 mg/day for the
first six months and 360 mg/day for the second six
"A potential magnesium deficiency is a matter
of concern for many individuals of all ages, but
for the elderly, it could be particularly serious,"
said Richard Rivlin, M.D., program director of the
Clinical Nutrition Research Unit at Memorial Sloan-Kettering
Cancer Center in New York, and chief of the Nutrition
Division at New York Hospital-Cornell Medical Center.
"The prevalence of heart disease, diabetes
and even leg cramps increases dramatically among
older persons, and these are all health conditions
in which magnesium deficiency has been found,"
He added that, "The Gallup Survey showed a
high general awareness of the importance of nutrients
such as vitamin C and calcium. But it is clear that
consumers are largely unaware of the role of magnesium
- a nutrient that is essential for the function
of other minerals like calcium, as well as the normal
operation of the heart and muscles."
A separate Gallup survey of 500 adults with diabetes
reported that 83 percent of those with diabetes
are consuming insufficient magnesium from food,
with many by significant margins. Sixty-eight percent
of the men and 56 percent of the non-pregnant women
said they were consuming threequarters or less of
their RDA for the mineral. "This is a concern,"
said Susan Thom, a registered dietitian, "Since
research has shown a strong association between
magnesium and the body's ability to use insulin
Insulin is a hormone required to convert glucose
(sugar) into energy. But for diabetics, the body
either does not manufacture sufficient amounts of
the hormone or is unable to process it.
"In fact," Thom continued, "a consensus
panel convened by the American Diabetes Association
has recommended that all persons with diabetes who
are at high risk for high blood pressure be tested
and, if a problem is found, treated with a magnesium
In spite of this recommendation, Thom added, only
five percent of the diabetics polled were aware
that magnesium deficiency is prevalent among diabetics.
And 99 percent - of whom more than half (53 percent)
have a history of heart disease and/or are taking
diuretics (water pills to induce urination) - said
they had not been advised by a health care professional
about a possible magnesium deficiency.
A magnesium deficiency in diabetics may result
in an increased risk for cardiac arrhythmias, high
blood pressure, myocardial infarction (heart attack)
and altered glucose metabolism, according to Robert
K. Rude, M.D., of the Southern California School
of Medicine in Los Angeles, in the October 1992
issue of Postgraduate Medicine.
He added that a magnesium deficiency is associated
with low blood levels of calcium and potassium.
Gastrointestinal loss and renal (kidney) wasting
are other considerations warranting oral magnesium
supplements, he said.
An initial dose may range from 300 mg/day to 600
mg/day with medical supervision. Divided doses are
suggested to avoid possible diarrhea. And, he said,
the mineral should be used cautiously by patients
with impaired kidney function.
Landy, Liz. "Gallup Survey Finds Majority
of American Diets Lack Sufficient Magnesium - At
Potential Cost to Health," Searle News, Sept.
. Rude, Robert K., M.D. "Magnesium Deficiency
and Diabetes Mellitus: Causes and Effects."
Postgraduate Medicine 92(5):217-223, October 1992.