Calcium

This is the fifth most plentiful element in the human body, after oxygen, carbon, hydrogen and nitrogen. It accounts for nearly 2% of the body weight, the average adult containing well over a kilo, 99% of which is in the skeleton. Calcium in involved in much of the body’s metabolism which means that the remaining 1% has many important functions. It has roles in the transmission of nerves messages, muscle contraction and relaxation this includes the heart muscle, blood pressure control, blood clotting and numerous enzyme and hormone actions. Because these functions are vital the circulation and nervous system, the blood level of calcium must be kept stable. If the blood level falls it is immediately replenished by borrowing calcium from the bones which are not static but very much alive and active. They are being constantly remodeled and the whole skeleton is renewed several times a year.

There is a lot of calcium in the food we eat. The best known source is dairy produce, but what is not well known is that the calcium in dairy products is not in the most easily absorbed form. Calcium is widely distributed in plant foods like green vegetables, grains, beans, nuts and seeds, mostly in an easily absorbed form. A few exceptions are spinach and wheat bran which are both rich in calcium but in a form that is not easily absorbed. There is a myth that calcium is not absorbed from plant foods but it would be a problem only on a restricted diet. A varied whole plant-food diet provides plenty of calcium.

There are several other very important factors in the body. To absorb calcium into the system, there must be enough vitamin D, the sunshine vitamin and once the calcium has been absorbed, it is important to limit the factors that cause it to be lost from the today.

In the west, osteoporosis a degenerative disease characterized by loss of calcium from the bones, is now very common. It has long been thought that the best way to prevent it was with dairy rich, high calcium diet. Interestingly Europe and America who lead the world in calcium intake, also lead the world in osteoporosis. In China, with only a third or a half the calcium intake, people have stronger bones and much less osteoporosis. Evidently calcium intake is not the whole story and the key factor is not how much you take in but how much of that you lose.

Some of the factors that cause calcium loss are dies high in animal protein, a high-phosphorus intake from meat and from soft drinks, high salt intake, caffeine, smoking and alcohol and very important, lack of exercise. These are all very common in the rich countries of the West. Factors to promote calcium retention are low protein intake (plant proteins are ideal as they are less concentrated and are lower in phosphorus), Low salt intake, avoiding caffeine, alcohol and phosphorus rich soft drinks, not smoking and taking regular, vigorous exercise. In China the average person gets far more exercise and eats far less animal produce, two of the most important factors in retaining calcium, and building and keeping healthy bones.

The World Health Organisation recommends 400-500mg of calcium a day for those who do not follow the rich, inactive Western lifestyle. Average intakes in the US and UK are far higher than this and the UK Food Standards Agency recommends 700mg of calcium a day for adults. Fortunately, there is no need to make detailed dietary assessments: if you are eating a varied diet based on whole, unrefined plant foods, you should have no problem in getting the calcium you need and if you get plenty of exercise and avoid the other calcium lowering factors, you should have no problem in retaining it.