Fecal calcium excretion effect

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. 

The effect of zinc toxicity on the calcium balance of young rats is presented in Table V. Marked increases in the fecal excretion of calcium was noted in the zinc-fed rats, and the overall effect of zinc toxicity was a substantial decrease in the apparent retention of calcium. The effects of zinc on calcium retention were noted as early as one week of the experimental period. 

Jacobsen, R., Lorenzen, J. K., Toubro, S., Krog-Mikkelsen, I., and Astrup, A. (2005). Effect of short-term high dietary calcium intake on 24-h energy expenditure, fat oxidation, and fecal fat excretion. Int. J. Obes. (Lond.) 29, 292-301. 

Comparative effects of calcium lactate and milk on apparent manganese utilization by humans are shown on Table II (7). In this study, 10 adult human subjects were fed 900 mg calcium from milk or 916 mg of calcium from calcium lactate/subject/day. Calcium provided by the basal diet was maintained constant. The increase in fecal manganese excretion with the calcium lactate supplemented diet in comparison to values when milk was the supplemental manganese source suggests that calcium supplied by milk had a lesser adverse effect on manganese absorption than did that from calcium lactate (Table II). 

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,... 

Table II shows data of the effect of a high phosphorus Intake on the zinc balance. The phosphorus supplements were given to three patients during different calcium Intakes, namely, during a low calcium Intake of 200 mg per day and during higher calcium Intakes of 800 mg and 2000 mg calcium per day. The phosphorus Intake of the subjects studied was approximately 900 mg per day In the control study and was 2000 mg per day during the high phosphorus Intake. In the control study, during a low calcium Intake and a normal phosphorus Intake of 900 mg per day and a dietary zinc Intake of 17 mg per day, the urinary zinc excretion was relatively high, 1.6 mg/day, the fecal zinc excretion was In the expected range and the zinc balance was positive,...

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