Health+and+Phosphorus


 * Phosphorus and Health

Phosphorus** the second most abundant element (after calcium) present in our bodies, makes up about 1 percent of our total body weight. It is present in every cell, but 85 percent of the phosphorus is found in the bones and teeth. In the bones, phosphorus is present in the phosphate form as the bone salt calcium phosphate in an amount about half that of the total calcium. Both these important minerals are in constant turnover, even in the bone structure. The body uses a variety of mechanisms to control the calcium-phosphorus ratio and metabolism. The ratio of these two elements in the diet has been the subject of much recent interest. The typical American diet provides too much phosphorus and not enough calcium, leading to reduced body storage of calcium; thus, many of the problems of calcium deficiency discussed earlier may develop. Phosphorus and calcium can compete for absorption in the intestines. High consumption of meats or soft drinks increases phosphorus intake and may contribute to this imbalance. The ideal ratio of calcium to phosphorus in the diet is 1:1. Phosphorus is absorbed more efficiently than calcium. Nearly 70 percent of phosphorus is absorbed from the intestines, although the rate depends somewhat on the levels of calcium and vitamin D and the activity of parathyroid hormone (PTH), which regulates the metabolism of phosphorus and calcium. Most phosphorus is deposited in the bones, a little goes to the teeth, and the rest is contained in the cells and other tissues. Much is found in the red blood cells. The plasma phosphorus measures about 3.5 mg. (3.5 mg. of phosphorus per 100 ml. of plasma), while the total blood phosphorus is 30-40 mg.. The body level of this mineral is regulated by the kidneys, which are also influenced by PTH. Phosphorus absorption may be decreased by antacids, iron, aluminum, or magnesium, which may all form insoluble phosphates and be eliminated in the feces. Caffeine causes increased phosphorus excretion by the kidneys.

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