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.

Let 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. Biyoloji 2 (Biology 2), p. 127

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. 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 created them.
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.( Helena Curtis, Sue Barnes, Invitation To Biology, 4. Edition, New York, Worth Publisher, INC, August 1985, p. 472) 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 a miracle.

Taking the Necessary Steps

Put yourself for a moment in the place of the cells that measure the amount of calcium. Imagine that your only job throughout your whole life, day and night, without stopping, sleeping or resting, is to calculate the amount of calcium in the blood. This will give you a better idea of the importance of the wonderful work these cells do.

If the parathyroid cells conclude as a result of their measurement that the amount of calcium has fallen too low, they immediately secrete parathormone. At this stage, the cells demonstrate another conscious activity: They "understand" that the level of calcium has fallen and take appropriate action to restore the deficiency.

Put yourself in the place of the parathyroid cells and think: If you were aware that the calcium level in the blood had decreased, what remedy would you use to increase the level of calcium?

To answer this question you would have to be a scientist with every means at your disposal to investigate the human body. If people had no knowledge about calcium in the body, it would be necessary to do years of research and receive assistance from the best biochemists in the world. There would be only one purpose for this effort-to find sources of calcium that could be used in the body.

Finally, at the end of your research you would learn that there is a great amount of calcium stored in the bones and that some calcium leaves the body in the urine. You would learn that calcium comes into the body from food through the intestines.
In the light of this, the three measures you could take to increase blood calcium are:

1. Borrow some of calcium from the bones.
2. Find a way to recover the calcium excreted in the urine.
3. Arrange to have more calcium taken from the food.
But each one of these functions takes us into a different field of expertise.

If the amount of calcium in the blood falls, there is only one molecule that puts all the remedies in place: parathormone, whose amino acid sequence can be seen on the right. This wonderful molecule has been created with the ability to control the bones, kidneys and intestines.

Before deciding on the first choice, you would have to persuade the bone cells to lend you a portion of the calcium they have stored in the bones. The bone cells (osteocytes) do not want to lose any of the calcium, which is very important to the bones. However, you must find a chemical formula that will allow the bone cell to release some of its stored calcium into the blood. In order to find this formula, you will have to be aware of all the chemical secrets of the bone cells down to the smallest detail and also the process by which the calcium is stored. Then you will have to devise a molecular formula to reverse this process. Moreover, you will have to obtain in a moment all the information pertinent to the inner structure of cells whose secrets human beings have been trying to discover for a hundred years. At the end of your lengthy researches, you will find the miraculous formula to persuade the bone cells to liberate some calcium-that formula is parathormone. (See figure 1)

But there are still other things you have to do. You must find two other formulas to ensure that the second and third functions are carried out.

To make the second choice feasible, you must persuade the cells in the kidneys to conserve the calcium in the urine and mix it with the blood again. Normally, there is no necessity for these cells to search for calcium in the urine. This time you must solve all the mysteries in the inner workings of kidney cells, which are quite different from bone cells. Then, you must find one molecule in an endless combination of molecules that can activate the kidney cells to find calcium in the urine. Finally, if you manage to produce this special formula, you will have witnessed one of the greatest wonders in the world, and the formula you obtain is exactly the same as the first formula you discovered-parathormone. Molecules having the same formula are able to make cells perform two totally different functions, a wonder that cannot be explained by the operation of evolution.
Now there remains a third thing you must do. You must get the body to retain more calcium from the food that it consumes.

When the level of calcium falls, the parathyroid hormone ensures that calcium is removed from the bones, that calcium in the urine is reabsorbed, and that calcium in food is absorbed. When the level of calcium in the blood is too high, calcitonin ensures that calcium in the bones be retained and that the bones speed up the absorption of calcium.

The mixing of the calcium in the food you eat with the blood occurs in the small intestine, but in order for the calcium to be reabsorbed, the intestinal cells need "activated vitamin D." Here, a major problem arises, because the vitamin D you obtain through your food is inactive.( Biological Science: A Moleculer Approach, p. 517)

 In order for your intestines to absorb more calcium (therefore, to increase the amount of it in the blood), this problem must be solved. A special molecule must exist that will change the chemical make up of inactivated vitamin D and activate it. Again, you must do much research and many experiments in order to design a special molecule that will activate the vitamin D. At the end of your research, you will find the formula of the molecule needed to activate the vitamin D (and to ensure the absorption of calcium by the cells of the intestine) is the same as the formula of parathormone.

Think about this: Three different unrelated ways have been discovered to increase the amount of calcium in the blood, but the key to causing these three different systems to function is the same-this key alters the operation of the three systems. What is more surprising is that, when the operation of these three systems (with their very different structures and ways of functioning) is changed, the result is the same-the amount of calcium in the blood increases. The fact that three different systems begin to work with the same key toward the same goal is a proof of the perfection and incomparable harmony of God's creation.

When the amount of calcium in the blood falls, the parathyroid cells demonstrate an incredible awareness. Using the appropriate key to alter the operation of each of the three systems, they ingeniously produce one molecule-parathormone.
In this way, they raise the level of calcium in the blood by ensuring that the bone cells release calcium, that the kidney cells extract more calcium from the urine, and that vitamin D is activated so that the digestive system can obtain more calcium.

There are three different ways to increase the level of calcium in the blood, and only one hormone can be matched these three ways. This is like saying that one single key can open three different locks.

How did the parathyroid cells find this ingenious formula? How do they know that this molecule will affect the bones, the kidneys and activate vitamin D? How is it that in the countless numbers of people who have lived in the course of history, the parathyroid has managed (except in cases of illness) to produce the right formula? How do the parathyroid cells know that the bones store calcium, that there is calcium in the urine that would be wasted, and that the cells of the small intestine need activated vitamin D to absorb calcium? How do they come up with the formula to make these three systems function? How do unconscious cells perform this feat of intelligence, which human beings could never manage?

Surely, the One Who manifests this intelligent design displayed in cells, Who creates cells, the calcium molecule and human beings from nothing, Who creates human beings in such a way that they need calcium, and Who also provides for this need with a perfect system is God, the Lord of the heavens and the Earth and of all that is in between. God's Majesty is exalted:
God, there is no god but Him, the Living, the Self-Sustaining. He is not subject to drowsiness or sleep. Everything in the heavens and the Earth belongs to Him. Who can intercede with Him except by His permission? He knows what is before them and what is behind them but they cannot grasp any of His knowledge save what He wills. His Footstool encompasses the heavens and the Earth and their preservation does not tire Him. He is the Most High, the Magnificent. (Qur'an, 2: 255)

Your god is God alone, there is no deity but Him. He encompasses all things in His knowledge.
(Qur'an, 20: 98)

A Control Mechanism

In earlier pages we have seen that a large part of the functioning of the hormonal system is under the control of the pituitary gland, but it will be noticed that the system in place to regulate the amount of calcium operates under the direction of a different control mechanism. The parathyroid glands measure the amount of calcium in the blood and decide what action to take. If the amount of calcium in the blood is too low, they secrete parathormone.

If the amount of calcium in the blood is more than is required, the secretion of parathormone is reduced. This time a different hormone comes into play: the thyroid gland secretes a hormone called "calcitonin," which has the reverse effect of parathormone. That is, it prevents bone cells from releasing calcium and makes them store it. The cells which make up the parathyroid gland know that they must go into action when the amount of calcium decreases, while the cells which compose the thyroid gland know that they must become active when the level of calcium increases. Who put this plan into the cells?
If the parathyroid went into action at the wrong time, when the amount of calcium was already too high, and parathormone began to be secreted, a serious danger for human health would result. Or, if parathormone and calcitonin were secreted at the same time, the body cells would not know what to do. If the cells that make up these glands were slow to go into action when the need arose (or did not notice that they were needed) a serious danger to health would again result. The harmonious functioning of the thyroid and parathyroid glands and the intelligence guiding the activities of the cells that make up these glands, are all proof that the human body was created.