Magnesium:
A Key to Calcium Absorption
By Nan Kathryn Fuchs, Ph.D.
Dr. Fuchs is a nutritional consultant in private
practice in Santa Monica, CA, and is author of "The Nutrition
Detective."
One of the most popular minerals in the news
today is calcium, needed for strong bones and teeth. We are told to take
increased amounts in our diet as a supplement to prevent osteoporosis
and eliminate muscle cramping during menstruation or from
over-exercising. Yet, calcium alone is often not enough. Without
magnesium, calcium may be not fully utilized, and underabsorption
problems may occur leading to arthritis, osteoporosis, menstrual cramps,
and some premenstrual symptoms.
Perhaps the single most significant reason
calcium malabsorption is so common today is due to a discrepancy between
what we eat and how we digest and absorb the nutrients in our food. Our
diets today are very different from those of our ancestors though our
bodies remain similar.
Thousands of years ago, our ancestors ate foods
high in magnesium and low in calcium. Because calcium supplies were
scarce and the need for this vital mineral was great, it was effectively
stored by the body. Magnesium, on the other hand, was abundant and
readily available, in the form of nuts, seeds, grains, and vegetables,
and did not need to be stored internally.
Our bodies still retain calcium and not
magnesium although we tend to eat much more dairy than our ancestors. In
addition, our sugar and alcohol consumption is higher than theirs, and
both sugar and alcohol increase magnesium excretion through the urine.
Our grains, originally high in magnesium, have been refined, which means
that the nutrient is lost in the refining process. The quality of our
soil has deteriorated as well, due to the use of fertilizers that
contain large amounts of potassium a magnesium antagonist. This results
in foods lower in magnesium than ever before.
ARTHRITIS AND
OSTEOPOROSIS

Strong Dense Bone
Fragile Osteoporotic
Bone
Two major health problems, arthritis and
osteoporosis, may be caused in part by a magnesium deficiency. When you
look at how calcium is absorbed these problems become easier to
understand, and often can be controlled through diet.
Magnesium is needed for calcium absorption.
Without enough magnesium, calcium can collect in the soft tissues and
cause one type of arthritis. Not only does calcium collect in the soft
tissues of arthritics, it is poorly, if at all, absorbed into their
blood and bones. But taking more calcium is not the answer; it only
amplifies the problem. In fact, excessive calcium intake and
insufficient magnesium can contribute to both of these diseases.
Magnesium taken in proper dosages can solve the problem of calcium
deficiency.
When calcium is elevated in the blood it
stimulates the secretion of a hormone called calcitonin and suppresses
the secretion of the parathyroid hormone (PTH). These hormones regulate
the levels of calcium in our bones and soft tissues and are, therefore,
directly related to both osteoporosis and arthritis. PTH draws calcium
out of the bones and deposits it in the soft tissues, while calcitonin
increases calcium in our bones and keeps it from being absorbed in our
soft tissues. Sufficient amounts of magnesium determine this delicate
and important balance.
Because magnesium suppresses PTH and stimulates
calcitonin it helps put calcium into our bones, preventing osteoporosis,
and helps remove it from our soft tissues eliminating some forms of
arthritis. A magnesium deficiency will prevent this chemical action from
taking place in our bodies, and no amount of calcium can correct it.
While magnesium helps our body absorb and retain calcium, too much
calcium prevents magnesium from being absorbed. So taking large amounts
of calcium without adequate magnesium may either create malabsorption or
a magnesium deficiency. Whichever occurs, only magnesium can break the
cycle.
In experiments reported in "International
Clinical Nutrition Review," a number of volunteers on a low-magnesium
diet were given both calcium and vitamin D supplements. AU the subjects
were magnesium-depleted and although they had been given adequate
supplements, all but one became deficient in calcium. When they were
given calcium intravenously, the level of calcium in their blood rose,
but only for the duration of the intravenous feeding. As soon as the
intravenous calcium was stopped, the levels calcium in the blood
dropped. However, when magnesium was given, their magnesium levels rose
and stabilized rapidly, and calcium levels also rose within a few days -
although no additional calcium had been taken.
Dr. Guy Abraham, M.D., a research gynecologist
and endocrinologist in premenstrual syndrome and osteoporosis has found
strong evidence to suggest that women with osteoporosis have a
deficiency of a chemical that is made when they take twice as much
magnesium as calcium. In fact, he has found that when calcium intake is
decreased, it is utilized better than when it is high. Dr. Abraham is
one of many doctors and biochemists who advocate taking more magnesium
to correct calcium-deficiency diseases.
A magnesium-rich diet can be helpful both for
arthritis and to help prevent osteoporosis. This consists of nuts, whole
grains such as brown rice, millet, buckwheat (kasha), whole wheat,
triticate, and rye, and legumes including lentils, split peas, and a
varieties of beans. A whole grain cereal or bread in the morning, a cup
of bean soup at lunch, a snack of a few nuts, and serving of brown rice,
millet, or buckwheat with dinner should help increase magnesium when a
deficiency is suspected.
At the same time, refined sugar and alcohol
should be reduced, and eliminated when possible to prevent magnesium
from being excreted in large quantities in the urine. You may also want
to re-evaluate the amount of dairy in your diet. If it has been
disproportionately high, reduce or temporarily eliminate it until some
of your symptoms are alleviated, or until you feel more of a balance has
been achieved through the inclusion of whole grains and legumes.
Oriental and Indian diets contain little or no dairy, yet arthritis and
osteoporosis are not major health problems in these cultures. Their
foods consist primarily of green vegetables, grains, tofu, and seafood,
and are twice as high in magnesium as our average diets.
Calcium causes muscles to contract, while
magnesium helps them relax. When calcium is taken for menstrual cramps
it knocks magnesium out of the cells and makes it more available for
immediate use. However, it depletes the body of magnesium and ensures
that the problem will recur the following month unless sufficient
magnesium is added to the diet. Taking calcium gives temporary relief of
menstrual cramps.
|
Recommended Calcium Intakes* |
|
Ages |
Amount mg/day |
| Birth - 6
months |
210 |
| 6 months -
1 year |
270 |
| 1-3 |
500 |
| 4-8 |
800 |
| 9-13 |
1300 |
| 14-18 |
1300 |
| 19-30 |
1000 |
| 31-50 |
1000 |
| 51-70 |
1200 |
| 70 or older |
1200 |
|
Pregnant & Lactating |
1000 |
|
14-18 |
1300 |
|
19-50 |
1000 |
A diet high in dairy and low in whole grains
can lead to excess calcium in the tissues and a magnesium deficiency.
The source of menstrual cramps may be coming from eating too much
cheese, yogurt, ice cream or milk, combined with insufficient whole
grains and beans. Or it could come from taking too much calcium without
enough magnesium. Modifying your diet and increasing your magnesium
supplementation may allow your menstrual cramps to disappear.
Premenstrual chocolate craving is a phenomenon
that has puzzled a great many women who are not controlled by this
overwhelming urge at other times of the month. Yet chocolate, which is
highest in magnesium of all foods, is often a sign of magnesium
deficiency. If your diet is high in calcium you may have poor calcium
absorption as well. The answer is not to eat more chocolate, but to
increase your magnesium by eating more whole grains, nuts, seafood, and
green vegetables, and by increasing your magnesium supplements. Your
chocolate cravings will vanish when you have enough magnesium in your
diet.
According to Dr. Mildred Seelig, executive
president of the American College of Nutrition, we need an average of
200 mg. more than we get from the average diet.
Foods highest in magnesium are nuts (especially
almonds and cashews), whole grains, seafood, and legumes (including
tofu). Eat more of these, while reducing sugar and alcohol, which
increase magnesium excretion. Don't overlook one vitamin or mineral for
another since all work together to supply you with the nutrients you
need. And consult your nutritionally- oriented physician about all
nutrients before trying them.
A balanced diet of fresh, whole foods is your
best maintenance diet. But if you have been taking large amounts of
calcium and ignoring magnesium you may want to reverse the proportions
until you achieve a better balance. Sufficient magnesium may be your
missing link.