Fecal phosphorus excretion level

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 VII shows the calcium balance of zinc-fed and non-zinc-fed rats supplemented with 0.8% calcium and/or phosphorus. Marked increases in fecal calcium and corresponding decreases in apparent calcium retentions in the zinc-fed rats could be reversed with calcium supplementation. Phosphorus supplements appeared to be associated with increases in calcium retention in the absence of zinc, but decreases in calcium retention in the presence of zinc without calcium supplementation. Decreases in fecal calcium were noted in animals fed calcium supplements in the presence of phosphorus or zinc. High levels of zinc were associated with increases in fecal calcium excretion in the absence of extra calcium or in the presence of extra phosphorus. Calcium supplementation was generally associated with a decrease in the urinary excretion of calcium, while zinc and phosphorus supplements were generally associated with an increase in urinary calcium excretion.

The amount that fecal phosphorus levels decline with phytase supplementation will depend on the percentage of phosphorus that is available in the base ration (Yi, 1996b). With available phosphorus at 0.05% of the ration in this study, excretion of phosphorus was reduced by about 25% in pigs receiving phytase compared to the control animals. When the base diet in this study contained 0.16% available phosphorus, excretion was reduced by 50% in pigs receiving phytase but no inorganic phosphorus. 

In the present study the effect of calcium and phosphorus on zinc metabolism was investigated In adult men by determining metabolic balances of zinc during different intakes of calcium and phosphorus. Three Intake levels of calcium, ranging from 200 to 2000 mg/day, and two Intake levels of phosphorus (800 and 2000 mg/day) were used during a constant dietary zinc Intake of 14.5 mg/day. Increasing the calcium Intake from 200 to 2000 mg and Increasing the phosphorus Intake from 800 to 2000 mg/day had no effect on urinary or fecal zinc excretion nor on zinc retention. absorption studies confirmed... 

Several zinc absorption studies, using oral doses of ZnCl2 were carried out. 65zq plasma levels were determined serially on the day of the oral administration of the zn tracer. Urinary and fecal 65zn excretions were determined for approximately 15 days. The subjects studied were fully ambulatory males who were In good nutritional state. They were normal according to all clinical and laboratory criteria. Including the serum levels of zinc, calcium, and phosphorus. The effect of three Intake levels of calcium on the zinc balance was studied, namely, of 200, 900,... 

The serum phosphate level of a worker with phossy jaw was within the normal range of values for an adult human (Hughes et al. 1962). Excretion of phosphate via urinary and fecal routes was reported qualitatively to be approximately normal. The daily output of phosphorus in the feces was about 1/4 to 1/3 of the total output in both urine and feces. 

The results obtained In zinc balance studies during different Intake levels of calcium and phosphorus were In agreement In Zn absorption studies. Figure 1 shows data of f> Zn plasma levels and of the fecal excretions following a single oral... 

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