Calcium is essential to good health, but if you are looking for calcium it can be confusing to decide in which form you take it. There are so many available and every one claims to be good for you, so why the difference? Why not just sell the best and let us all know what it is? Well, this same argument could be applied to all supplements that are sold in different forms, and also to many foodstuffs.



The supplement best for you might not be the best for the next person due to dietary requirements each persons diet is different, so it is better to learn about what is available then make your choice based upon knowledge rather than ignorance. It is not only the source of the calcium you have to bother about, but also the other vitamins that have be present to make sure that that the calcium is absorbed by the body in the way that you want it to be.

To understand that then you need to learn why the body needs calcium, other than just the bones and teeth that everybody knows about. After all, why else do we need calcium? It is only contained in bones and teeth ? right? Wrong!

Although 99% of calcium is contained in your bones and teeth, 1% is contained in the blood, muscles and central nervous system. With out that 1% we would all die. Without teeth we would not. Calcium is essential for blood clotting and for the proper function of our muscles, brain and central nervous system. Calcium combines with phosphorus to create healthy bones and teeth, and is essential early in life to build up a strong skeleton. Note that phosphorus is also necessary so we also need an adequate supply of that mineral.

Calcium is essential to allow muscles to properly contract. Without that ability, muscles could not work, and a deficiency of calcium causes muscle cramps and spasms. The movement of the smooth muscles is regulated by a protein that is bound to calcium. This is just one of the uses of the calcium in the body that most people are unaware of.

Calcium also takes part in the binding process of the blood platelets during the coagulation of blood. Although most people are aware of the need for vitamin K and fibrin, in fact calcium is also essential in its interaction with the platelets in the coagulation cascade that eventually results in a blood clot that stops bleeding. Basically, without calcium, the blood could not form a clot. In addition to its effect on blood clotting, calcium also plays an essential part in the movement of ions through the membranes of nerve cells, and without it intercellular communication could not occur. Our nerve impulses would not occur and the body again would not be in a working condition.

However, the body has a way of modulating the calcium level in the blood past a minimum level needed for effective nerve cell communication, and below a certain level it can even use the calcium in the bones to divert to the more needy areas of the body. It is therefore not possible for the body to fail through a lack of calcium. The skeleton would disintegrate first. Nevertheless, nobody wants a disintegrating skeleton since that would be counterproductive to effective movement of the body, so a good source of calcium is essential for overall bodily health, not just that of the teeth and the bones.

There are many sources of calcium, but some are more suitable for absorption by the body than others. Chalk, or calcium carbonate, is an excellent source of calcium, but will fail to promote bone growth if your diet does not contain sufficient potassium, vitamin D, magnesium and strontium needed to make it work to build healthy bones. It is the most common on the shelves, and likely the cheapest, but not necessarily the best source. It is basically chalk or limestone, and only 10% of the supplement will actually become available for your body to use.

The bioavailability of a calcium supplement is a figure that indicates how much of the calcium is actually absorbed by the body during digestion. It is important that the supplement is digested and absorbed properly or the calcium will not be available for use. This availability is called the ?bioavailability?. Calcium citrate has a bioavailabilty of 50%, but the size of the citrate part of the molecule is so large that only 10.5% of the molecule is available to the body as calcium. Not much more than the carbonate.

Calcium aspartate is highly soluble and produced by reacting calcium with aspartic acid to form the soluble salt. It is much easier to assimilate and be absorbed by the body than any of the forms above. The amino acid, aspartic acid, delivers the calcium exactly to where it is needed, where it is absorbed and used. Although a bioavailability figure is not available, it is not the amount of calcium that is significant here but the fact that it comes with its own transportation system and is immediately available where needed.

If you want to calculate the availability for yourself, find the molecular weight of the particular calcium product, and then the weight of the calcium contained within it. For example, in calcium carbonate, CaCO3, the molecular weight is 100 (40 + 12 + 3x16) and the atomic weigh of calcium is 40, so the amount of calcium present in 1000g calcium carbonate is 40% or 400g. Only 25% of calcium carbonate is absorbed, so only 10%, or 100g, of calcium is available for each 1000g supplement.

Calcium citrate on the hand (Ca3(C6H5O7)2.4H2O) has a molecular weight of 570, so the amount of calcium present is 3*40*100/570 = 21%. Since the bioavailability of calcium citrate is 50%, the amount of calcium available is only 10.5%, or 105g in 1000g citrate. You can carry out the same calculation on all the molecules if you know how much is absorbed by the body.

The bioavailability is calcium aspartate is 85%. Its molecular formula is [C4H6NO2]2Ca, and molecular weight 304. The calcium availability is therefore 40*100/304 = 13.16%. If 85% is absorbed, then 1000g provides 80% of 13.16 x 10 = 115.6g. The aspartate therefore wins it.

Amino acid chelates can also be used as a source of calcium, and its bioavailability is improved tremendously by including vitamin D and magnesium in the supplement. The bioavailability of these calcium chelates are not quoted, but is claimed to be high. Whether or not it is as high as the aspartame is debatable, though it is claimed to be.

Calcium is a very important mineral for human health, and there are several different supplements that can be used. The bioavailability of the calcium is different in each supplement, though the organic forms, calcium aspartate and amino acid calcium chelates appear to be the highest. When looking for a calcium supplement look for one with additional minerals added as mentioned above to help improve absorption and usability by the body.