The presence of calcium ions is necessary to cause muscles
to contract; magnesium ions are essential to induce muscles to
Altura BM, Altura BT, New perspectives on the role of magnesium
in the pathophysiology of the cardiovascular system, II. Experimental
aspects, Magnesium, 4:245-271, 1985.
It is now becoming clear that a lower than normal dietary intake
of Mg can be a strong risk factor for hypertension, cardiac arrhythmias,
ischemic heart disease, atherogenesis and sudden cardiac death.
Deficits in serum Mg appear often to be associated with arrhythmias,
coronary vasospasm and high blood pressure (from the paper's abstract):
Altura BM, Altura BT, Cardiovascular
risk factors and magnesium: relationships to atherosclerosis,
ischemic heart disease and hypertension, Magnes Trace Elem,
Hypertension can result from an increase in sodium, or a decrease
in potassium or magnesium, or either an increase or a decrease
Shils ME, Experimental production of magnesium deficiency in
man, Annals of the NY Academy of Sciences, 162:847-855, 1969.
When there is a deficiency of magnesium, the calcium must be
blocked so that they still balance and you do not get the resultant
muscle spasm. If the spasm is in the coronary arteries, it causes
angina or arrythmia. If it's in other arteries, it causes hypertension:
Iseri LT, French JH, Magnesium: Nature's physiologic calcium
blocker, Amer Heart Journal, 188-193, July 1984.
Magnesium plays a major role in regulating the vascular tone
(hypertension), electrical conductivity (cardiac arrythmia), and
calcium deposits in blood vessels (arteriosclerosis):
Rayssiguier Y, Role of magnesium and potassium in the pathogenesis
of arteriosclerosis, Magnesium, 3:226-238, 1984.
Altura BN, et al, Magnesium deficiency and hypertension: Correlation
between magnesium deficient diet and microcirculatory changes
in situ, Science, 223:1315-1317, 1984.
Turlapaty PDMV, Altura BM, Magnesium deficiency produces spasms
of coronary arteries: relationship to etiology of sudden death
ischemic heart disease, Science, 208:198-200, 1980 (see full abstract).
Dietary magnesium (Mg) deficiency is more prevalent than generally
suspected, and can cause cardiovascular lesions leading to disease
at all stages of life (from the paper's abstract).
Seelig M, Cardiovascular
consequences of magnesium deficiency and loss: Pathogenesis, prevelence,
and manifestations - magnesium chloride loss in refractory potassium
repletion, Am J Cardiol, 53:4g-21g, 1989.
In a clinical study, magnesium was administered to 8000 surgical
patients over 15 years. The results showed little or no effect
on patients with low or normal blood pressure, but patients with
high blood pressure usually had normal blood pressures by the
time surgery was performed:
Horn B, Magnesium and the cardiovascular system, Magnesium,
Insufficient magnesium can cause arterial calcification, which
makes blood vessels hard and brittle, resulting in hypertension:
Boskey AC, Pasner AS, Effect of magnesium on lipid-induced
calcification, Calcif. Tissue Int., 32:139-143, 1980.
Magnesium sparing of calcium deposits has been known a long
Leonard F, Initiation and inhibition of subcutaneous calcification,
Calc. Tiss. Res., 10:269-279, 1972.
Magnesium is present in many foods. Even so, only 40% of people
in the U.S. consume enough to meet the RDA:
Science News, vol 133, June 1988.
Just because you consume magnesium doesn't mean that you absorb
it; low stomach acid is very common:
Nicar MJ, Pak CYC, Oral magnesium deficiency, causes and effects,
Hospital Practice, 116A-116P, 1987.
About 50% of body magnesium is in your bones, 49% is inside cells,
and 1% is extracellular (in serum). Because of homeostasis, if
your serum magnesium level gets too low, magnesium can be pumped
from inside your cells into the serum. Bones are only used as
a magnesium source when intracellular levels drop too low. And
intracellular levels do not have to be dramatically low to induce
Your kidneys can also leak magnesium. This can happen by a
number of different types of chemical exposures, or perhaps more
commonly, by prescription diuretics. Diuretics deplete magnesium
as well as potassium, which can be fatal:
Mountokalakis TD, Diuretic-induced magnesium deficiency, Magnesium,
The total body store of magnesium in a 70 kg man is about 26000
mg. About 1% of total body stores (appx 260 mg) are in extracellular
fluid (serum); the rest is split between bone and intracellular
stores. Assuming that you might give off a liter of sweat in a
day when exercising, and that there is about 20 mg of magnesium
per liter, that would be 20/260, or about 7.7% of serum magnesium
can be lost in a day; a substantial loss - especially if you are
already magnesium deficient:
Linder MC, Nutritional Biochemistry and Metabolism, p192, 1991.
The National Research Council has recommended minimum daily
consumption of 150-250 mg of magnesium for children under ten,
300 mg for adult females, 400 mg for adult males, and 450 mg for
pregnant or lactating women. If you assume a woman weighs 60 kg
and a man 70 kg, this corresponds to 5 mg/kg/day.
Ryan MF, Ann Clin Biochem 28:19-26, 1991).
However, after an extensive review of the literature, one researcher
concluded that an intake of 6-10 mg/kg/day is optimal (that would
be 360 mg to 700 mg/day), and also that it is a misconception
that the daily requirement of magnesium is the amount that prevents
signs and symptoms of deficiency or hypomagnesemia.
Seelig MS, Magnesium Bull 3 suppl 1A, 26-47, 1981.
Regardless of the adequecy of the RDA for magnesium, the majority
of people in this country have an intake of magnesium below the
RDA. In 1977-78 the USDA conducted a nationwide food survey that
showed a lower than recommended consumption of magnesium in the
U.S. Only 25% of the surveyed population had a magnesium intake
at or greater than the RDA. Almost 40% were consuming less than
70% of the RDA. Most people would agree that food quality nationwide
has decreased since that time:
Pao EM, Mickle SJ, Food Technol 35:58-69, 1981.
One of the reasons for the low magnesium intake is that when
whole foods are processed, they lose about 80% of their trace
minerals, including magnesium. Undiagnosed problems with magnesium
absorbtion or undiagnosed renal magnesium leaks can further contribute
to hypomagnesemia, even when recommended intake requirements are
Schroeder JA, Nason AP, Tipton IH, Essential Minerals in Man
- Magnesium, J Chron Dis 21:815-841, 1969.
Discussion of essential hypertension, with normal serum and
intracellular magnesium levels:
Ozono R, et al, Systemic magnesium deficiency disclosed by
magnesium loading test in patients with essential hypertension,
Hypertension Research 18:39-42, 1995.
Vasospastic angina, ischemic heart disease (see full abstract)
Tanabe K , Magnesium content of erythrocytes in patients with
vasospastic angina, Cardiovasc Drugs Ther, 5/4:677-680, 1991.
Coronary heart disease, diminished left ventricular stroke
volume (lower than 55%). Serum magnesium normal, intracellular
magnesium significantly lower (1.59mg/dl) than healthy subject
Manthey J, Magnesium in serum of patients with coronary artery
Other miscellaneous literature references:
Abraham GE, The importance of magnesium in the management of
primary postmenopausal osteoporosis, Journal of Nutritional Medicine,
2, 165-178, 1991.
Cannon LA, Heiselman DE, Dougherty JM, Jones, J, Magnesium
levels in cardiac arrest victims: Relationship between magnesium
levels and successful resuscitation, Ann Emerg Med, 16:1195-1198,
Rhinehart RA, Magnesium metabolism: A review with special reference
to the relationship between intracellular content and serum levels,
Arch Int Med, 148:2415-2420, 1988.
Leary WP, Reyes AJ, Magnesium and sudden death, SA Med J, 64:697-698,
1983 (see full abstract).
Roubenoff R, et al, Malnutrition among hospitalized patients:
Problem of physician awareness, Arch Intern Med, 147:1462-1465,
Oral magnesium successfully relieves premenstrual mood changes,
Obstet Gynecol, 78/2:177-181, 1991 (see full abstract).
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