Phosphorus in bone

In 1771, C. W. Scheele mentioned the occurrence of phosphorus in bones, while T. Bergman said that the fact was discovered by J. G. Gahn, about 1770. 

Phosphates are important because they affect the absorption of calcium and other elements. The absorption of inorganic phosphorus depends on the amount of calcium, iron, strontium, and aluminum present in the diet. Chapman and Pugsley (1971) have suggested that a diet containing more phosphorus than calcium is as detrimental as a simple calcium deficiency. The ratio of calcium to phosphorus in bone is 2 to 1. It has been recommended that in early infancy, the ratio should be 1.5 to 1 in older infants, 1.2 to 1 and for adults, 1 to 1. The estimated annual per capita intake in the United States is 1 g Ca and 2.9 g P, thus giving a ratio of 0.35. The danger in raising phosphorus levels is that calcium may become unavailable. 

The skeleton is not a stable unit in the chemical sense, since large amounts of the calcium and phosphorus in bone can be liberated by reabsorption. This takes place particularly during lactation and egg production, although the exchange of calcium and phosphorus between bones and soft tissue is always a continuous process. Resorption of calcium is controlled by the action of the parathyroid gland. If animals are fed on a low-calcium diet, the ionic calcium concentration in the extracellular fluid falls, the parathyroid gland is stimulated and the hormone produced causes resorption of bone, liberating calcium to meet the requirements of the animal. Since calcium is combined with phosphorus in bone, the phosphorus is also liberated and excreted by the animal. 

The recipe was secretly purchased and otherwise passed among a select number of entrepreneurs until finally in 1737, some 68 years after its initial discovery, the secret was sold to the French Academy of Sciences, which made it public. In 1769 Karl Scheele and Johann Gahn found phosphorus in bones, but it is remarkable that for a full century the only way to make this element involved the processing of human urine By the early 1800s, the manufacture of matches in England made the demand for phosphorus so great that European battlefields were being combed for human remains. Thankfully, it is now manufactured by the relatively... 

Phosphorus, like nitrogen, is an essential constituent of living matter where it may be partly in combination (as phosphate groups) with organic groups, for example in lecithin and egg yolk, or mainly in inorganic form, as calcium phosphate(V), in bones and teeth. 

Phosphorus. Eighty-five percent of the phosphoms, the second most abundant element in the human body, is located in bones and teeth (24,35). Whereas there is constant exchange of calcium and phosphoms between bones and blood, there is very Httle turnover in teeth (25). The Ca P ratio in bones is constant at about 2 1. Every tissue and cell contains phosphoms, generally as a salt or ester of mono-, di-, or tribasic phosphoric acid, as phosphoHpids, or as phosphorylated sugars (24). Phosphoms is involved in a large number and wide variety of metaboHc functions. Examples are carbohydrate metaboHsm (36,37), adenosine triphosphate (ATP) from fatty acid metaboHsm (38), and oxidative phosphorylation (36,39). Common food sources rich in phosphoms are Hsted in Table 5 (see also Phosphorus compounds). 

Phosphorus Rat Lead retention Low dietary phosphorus enhances lead retention no effect on lead resorption in bone Quarterman and Morrison 1975... 

Increasing both dietary Ca and P causes a decrease in PTH-mediated bone resorption polyphosphates and phosphorus in food cause greater reductions than does inorganic orthophosphate, as these sources are slowly released in digestion. 

Although much attention has been directed toward the relationship between calcium intake and osteoporosis, little consideration has been given to the possible influence of dietary phosphorus on the development of this disease in either man or animals. In a study designed to determine the optimal concentration of calcium and phosphorus in the diet of adult mice, aging animals were found to undergo a greater loss of bone when the Ca/P ratio was 1 1 than... 

Meat and such high protein plant foods as soy are excellent sources of phosphorus as well as protein. The phosphorus in meat is readily absorbed from the gastrointestinal tract however, much of the phosphorus in plant products is in a bound form which may inhibit the absorption of calcium as well as phosphorus. This study was designed to determine the effect of different levels of calcium and phosphorus with plant protein or animal protein on bone breaking strength and calcium and phosphorus utilization of weanling mice. 

High intakes of protein, particularly animal protein coupled with low phosphorus intakes have been credited as resulting in high urinary losses of calcium and poor calcium balances which can be overcome by increasing intakes of either calcium or phosphorus or lowering protein intake in the adult human (9,15,16). In the present study, not only did the animal protein diet result in bones more resistant to breakage than did the plant protein diet, but the animal protein fed animals were seemingly less affected by variations in intake of phosphorus and calcium than were the plant protein fed animals. 

High levels of dietary zinc were associated with marked decreases in bone calcium deposition and in the apparent retention of calcium in male weanling albino rats. Marked increases in fecal calcium levels were also observed in the zinc-fed rats. Excessive dietary zinc was associated with a shifting of phosphorus excretion from the urine to the feces. This resulted in an increase in fecal phosphorus and provided an environmental condition which would increase the possibility of the formation of insoluble calcium phosphate salts and a subsequent decrease in calcium bioavailability. The adverse effect of high dietary zinc on calcium status in young rats could be alleviated and/or reversed with calcium supplements. 

Table II shows the effects of varying dietary levels of zinc on weight gains and on bone calcium and phosphorus levels of young rats at the end of a 4-week experiment. Increases in dietary zinc were associated with significant linear decreases in bone calcium and phosphorus deposition. The bones taken from animals at the time of sacrifice and used for the mineral analyses were very soft in nature and could be easily squeezed with the fingers.

Table IV shows data from another experiment in which the levels of calcium and phosphorus supplements were 0.4%, 0.8%, and 1.2%. Supplements of calcium resulted in significant Improvements in bone calcium levels of zinc-fed rats, whereas phosphorus supplements had little effect on bone calcium levels in zinc-fed rats. Increasing the calcium supplement from 0.4% to 0.8% resulted in additional increases in bone calcium deposition, and a level of 1.2% added calcium resulted in the same increase in bone calcium levels of rats fed 0.75% zinc as did the 0.8% calcium supplement. Mean bone calcium values of zinc-fed rats supplemented with either 0.4% calcium and phosphorus or 0.8% calcium and phosphorus were essentially the same as mean bone calcium values of zinc-fed rats supplemented with either 0.8% or 1.2% calcium. A combination supplement of 1.2% calcium and phosphorus was found to completely alleviate the decrease in bone calcium deposition associated with the feeding of a 0.75% level of zinc. Calcium supplements partially alleviated the decrease in bone phosphorus level associated with the feeding of the...

The data presented in this paper indicate that excess levels (0.75%) of dietary zinc result in decreases in the bioavailability of calcium and phosphorus in rats and interfere with normal bone mineralization. High dietary levels of calcium or zinc appeared to cause a shift in the excretion of phosphorus from the urine to the feces, while the presence of extra phosphorus tended to keep the pathway of phosphorus excretion via the urine. The presence of large amounts of phosphorus in the Intestinal tract due to high intakes of zinc would increase the possibility of the formation of insoluble phosphate salts with various cations, including calcium, which may be present. A shift in phosphorus excretion from the feces to the urine, however, could result in an environmental condition within the system which would tend to increase the bioavailability of cations to the animal. The adverse effect of zinc toxicity on calcium and phosphorus status of young rats could be alleviated with calcium and/or phosphorus supplements. 

Phosphorus homeostasis (see Section 5.2.1) is intimately involved with that of calcium. The most important reservoir of calcium and phosphorus within the mammalian body is in bone—85% of the body s calcium and 85-90% of phosphorus is found there. Ninety-nine percent of bone calcium remains in the mineral phase as Ca3(P04)2, and so on, but the other 1% can rapidly exchange with extracellular calcium. 

Phosphorus is a critically important element in every cell of the body and also in the form of hydroxyapatite in bone and in all other functions as phosphate. The concentration of phosphate in blood is 1.0 to 1.5 mmol/L existing as H2P0( and HPOl" the equilibrium between the two acts as a proton buffer... 

Monitoring Closely monitor patients coinfected with HBV and HIV who discontinue tenofovir with both clinical and laboratory follow-up for at least several months. Monitor patients at risk for, or with a history of, renal dysfunction and patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus. Consider bone monitoring for HIV infected patients who have a history of pathologic bone fracture or are at substantial risk for osteopenia. 

A common source of organic phosphorus is bone meal (approximately 9-14% P) and bone ash (approximately 18%). The bird excrement guano contains about 2-3% P as ammonium and calcium phosphates. Fresh solid dairy cattle manure has approximately 0.13% P (moisture = 81.7%), and solid swine manure has about 0.33% P (moisture = 71.8%), which will be in both organic and mineral forms. 

Phosphorus is an essential element present in all living matter and is vital in biological and ecological processes. It occurs in DNA and other nucleic acids, and in bones. 

Cerium in Plants and Animals. Professor Alfonso Cossa, finding the rare earths of the ceria series to be present in many apatites, and realizing the close association in nature between these earths and calcium and phosphorus, tested for them and detected their presence in bone (66). He also detected them in the ash of barley, beech wood, and tobacco. With the aid of C. Schiapparelli and G. Peroni of the University of Turin, he demonstrated their presence in human urine (66, 67, 68). 

About 98% of the 1.5 kg of calcium and 85% of the 1 kg of phosphorus in the human adult are found in bone. Bone is composed of two distinct tissue structures cortical... 

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