There is no flashing red light to warn you of a calcium deficiency. In fact, it usually not detectable until irreversible damage has already been done. Calcium deficiency is hard to detect because the calcium level in the blood may appear to be normal even in extreme cases. Why? Because the body has a calcium bank in the form of teeth and bones. The need for calcium to control muscular contractions (including the heart), blood-clotting, transmission of nerve impulses and other requirements, take priority. In short, a series of biochemical reactions is triggered and a check is written on your calcium bank. Your bones will be robbed to supply your blood and you will be operating on a perilous calcium overdraft.

How likely is this to happen to you? It may be decades before you know for sure when loose teeth, receding gums or a fractured hip demonstrate how brittle and chalky your bones have become. There is no known cure for osteoporosis but it seems to be afflicting people at increasingly younger ages. The progression towards this disaster takes years, but you may be sure it is going on unnoticed right now in a substantial percentage of our population. Here are the facts that explain why the problem of calcium deficiency is so widespread. First of all, the typical American diet supplies a meager 450-550 milligrams - far short of the 1000 milligrams recommended by the current RDI. Most nutritional experts believe 1000-1500 milligrams are closer to what is really needed but, even if you adjust your diet so that you took in enough calcium, you run into a "Catch 22".

Calcium is not easily absorbed. Perhaps no more than 10-20% of that which is found in the foods consumed is actually metabolized. There are a lot of reasons why this is so. A meal high in fats can form insoluble calcium soaps causing the calcium to pass through the system unabsorbed. The calcium in certain vegetables may be inhibited from release by oxalates found naturally in such foods as rhubarb, kale, spinach, and broccoli or phytates in grains and cereals and, of course, a supply of Vitamin D must be present for the absorption and use of calcium. That is why milk and most calcium supplements are fortified with this vitamin.

In addition, calcium requires an enzyme rich environment for absorption - a special problem for older people who tend to have a lower production of digestive enzymes. There is more. The amino acids leucine, arginine and serine are needed for the formation of calcium-amino acid complexes. Magnesium and phosphorus must be present in an appropriate ratio. Without all these and other factors, you may lose a lot of the benefit no matter how much calcium you may be ingesting. Is it any wonder that so many people today are overdrawn on their calcium bank?

You will find quite an array of calcium supplements on the shelf in your health food store. Some will be simple calcium carbonates. Others will be calcium carbonate in so-called natural forms, such as oyster shells or eggshells. You will find bone-meal, di-calcium phosphate, dolomite, calcium lactate, calcium glutonate and many others. True, they all contain calcium but they vary in the amount of actual calcium content from 95% Coral Calcium to around 9% for calcium glutonate. But not all forms have the same amount of absorbability.