PHOSPHORUS DEFICIENCY

condition in which an organism does not receive an adequate supply of phosphorus, a mineral vitally important to the normal metabolism of numerous compounds and (in solution) an acid that, with sulfur, must be neutralized by the base-forming ions of sodium, potassium, calcium, and magnesium. About 70 percent of retained phosphorus combines with calcium in bone and tooth structure, while nitrogen combines with most of the remaining 30 percent to metabolize fats and carbohydrates. Phosphorus is the principal element in the structure of the nucleus and cytoplasm of all tissue cells. In addition, this mineral probably has the power to regulate hydrogen ion concentration and vitamin absorption in living tissues. It is also a universally distributed component of skeletal, nerve, and muscle tissues. A reduced concentration of phosphate in the blood serum is a disorder known as hypophosphatemia (q.v.). Deficiencies relating to the ratio of phosphorus to calcium may cause bone diseases such as rickets in children and osteoporosis or osteomalacia in adults. Sometimes an improper ratio causes bone fragility and tetany (severe muscle spasms in fingers and toes). Dietary sources of phosphorus include milk products, egg yolk, fresh foods, legumes, nuts, and whole grains.