The amount of calcium in the blood is a very important
factor in human survival. In order for a human to survive,
he needs to not only breathe and drink water, but he
must also have a certain amount of calcium in his blood.
If the level of calcium in the blood falls below what
is required, death will result. Now, let us think of
this hypothetical example: A container in front of you
contains one liter of blood. This blood is to be transfused
into a patient waiting for an operation. It has been
discovered that there is a deficiency of calcium in
this blood, but the amount of the deficiency has not
been determined. You are asked to make a guess and supply
the deficiency. You have been given a large container
of powdered calcium to use.
How would you make this decision?
First, you would have to measure the amount of calcium
in the blood in front of you. But you would need such
advanced technological tools that you would have neither
the time nor the opportunity to do it. In this situation,
you would be completely helpless. The fact that you
are unable to measure the amount of calcium in the blood
in front of you may result in the patient's death.
us change our example slightly: Now you are given one
liter of blood which contains no calcium, and you have
to add the right amount of it. How many spoonfuls of
calcium would you take from the container and add to
the blood? What is the correct amount of this vital
substance that must be added to one liter of blood?
You will never encounter this situation; the example
has been given just to emphasize the importance of the
amount of calcium in the blood. If a liter of blood
were placed before you containing no calcium, the amount
of calcium you would have to mix with it would be one
tenth of a gram. In the five liters of blood in your
body, there needs to be a total of only half a gram
of calcium. If there is any more or less than this,
serious illness or even death may result. Clearly, the
human body has been created in a marvelously delicate
balance. A person weighing 80 kilos requires only half
a gram of calcium circulating in his blood-any more
or less, and he will die.
Calcium ensures the operation of several
vital functions in our bodies. Without calcium, the
blood would not clot and a person could die from blood
loss from to a small wound or even a scratch. Calcium
also plays an important role in the transmission of
nerve impulses. If nerve impulse transmissions were
severed, death would result. Calcium also ensures that
the muscles function and that the bones are healthy.
The body of an adult person contains up to two kilograms
of calcium, and of this, ninety-nine per cent is stored
in the bones. The remainder is used in functions relative
to body metabolism. Approximately 0.5 grams of calcium
in the blood is sufficient for bodily functions.18
Above, we see the parathyroid glands. When the
amount of calcium in the blood falls, the parathyroid
releases a wonderfully designed hormone called
parathormone. It is remarkable that a piece of
flesh can recognize calcium, measure it and make
a decision based on the results of that measurement.
As we said before, in 100 milliliters of blood, there
is 10 milligrams of calcium-the equivalent of 0.1 gram
in a liter. If the proportion falls from 10 mg. to 6-7
mg. (the total amount of calcium in the blood falls
by 0.2 grams), tetany occurs, characterized by symptoms
of painful muscle contractions and convulsions. These
contractions happen first in the heart muscles and the
muscles of the respiratory tract. The irregular contraction
of these muscles makes the heart beat erratic and inhibits
the respiratory function. Without treatment, the patient's
heart will stop (or he will not be able to breathe).
In either case, death results. As we can see, in order
for such vital functions as heart beat and respiration
to occur, only half a gram of calcium is needed.
If the amount of calcium in the blood
increases to 12 mg. in 100 ml. (that is, if the total
amount of calcium in the blood increases by one tenth
of a gram), kidney stones could develop, the activity
of the nervous system reflex could slow down, and the
muscles could atrophy and (as a result) lose their strength.
When the amount of calcium rises to 17 mg. per 100 ml.
of blood, calcium phosphate spreads to every part of
the body and poisons it.19 The
fact that the human body is so dependent on a substance
(and that this substance is used in several of this
body's functions) demonstrates two important points:
that human beings are created according to a wonderful
plan, and that they are totally dependent on God Who
After we have seen the importance of the amount of
calcium in the blood, this question inevitably comes
to mind: what is the mechanism that determines this
amount that is so vital for life? The answer to this
question reveals another wonder of creation. Buried
inside the thyroid gland is another hormonal gland called
the parathyroid. In order to ensure the balance of calcium
in the body, this gland, working cooperatively with
others, puts a highly intelligent plan into effect.
The only function of the parathyroid is to measure how
much calcium there is in our blood; it does this day
and night throughout our whole lives, to keep the proportion
of calcium at the ideal level.
If you placed the material seen on the left in
front of someone and asked him what it was, he
would not be able to recognize it unless he had
special training. But the cells in our body immediately
recognize calcium atoms from among the hundreds
of materials in the blood.
Through the agency of a specially
designed hormone that it produces (parathormone), the
parathyroid regulates the level of calcium in the blood.
If the level of calcium in the blood drops, it immediately
secretes parathormone.20 This
demonstrates a very important point: at the beginning
of this section we asked whether you could determine
the amount of calcium in a container of blood placed
in front of you. We determined that, without laboratory
devices specially designed for this task, you would
not be able to succeed. Yet the tiny parathyroid can
make a calculation that humans cannot do except in a
laboratory. The cells that compose the parathyroid gland
not only produce a hormone, but they also make measurements
relative to the place where the hormone will be used.
How does a cell pick out the calcium atoms in the river
of blood flowing in front of it? How can cells without
eyes, ears or hands recognize calcium atoms among the
millions of kinds of other substances in the blood such
as salt, glucose, fat, amino acids, proteins, hormones,
enzymes, lactic acid, carbon dioxide, nitrogenous waste,
sodium, potassium, urea, uric acid, iron and sodium
bicarbonate? How does a cell recognize calcium? How
does it know how much calcium there should be in the
blood? With what consciousness does it measure the calcium?
With what intelligence does it decide whether there
is too much or too little calcium present? Cells are
tiny, only one percent of a millimeter in size, without
conscious intelligence. The fact that they can successfully
measure the amount of calcium in the blood is in itself
2 (Biology 2), p. 127
19 Biyoloji 2 (Biology 2), p. 129
20 Helena Curtis, Sue Barnes, Invitation To Biology,
4. Edition, New York, Worth Publisher, INC, August 1985,