Negative Phosphorus Balance Research Articles

The Effect of Level of Intake on Calcium and Phosphorus Metabolism in College Women ,

Calcium and phosphorus metabolism were studied on 17 college women from two states. Five subjects, two in Ohio and three in Minnesota, were maintained for a period of 8 weeks on a basal diet which supplied approximately 300 mg of calcium and 800 mg of phosphorus daily. A second group of 6 subjects, three in Ohio and three in Minnesota, were maintained on the basal diet for 4 weeks. This was followed immediately by a 4-week period during which the basal diet was supplemented by 1,200 mg calcium, making the total calcium intake 1,500 mg daily. A third group of 6 subjects, following the 4-week period on the basal diet, received supplements of calcium and phosphorus, making the total intake 1,500 mg of calcium and 1,400 mg of phosphorus. One week was shown statistically to be an adequate period for adjustment to the calcium and phosphorus levels in the basal diet. Negative calcium balances were observed on the basal diet, whereas more positive than negative phosphorus balances were noted. Increasing the calcium intake from 300 mg to 1,500 mg without altering the phosphorus intake resulted in a statistically significant increase in calcium retention. Urinary calcium excretion also increased significantly. Phosphorus retention, however, was unchanged, but there was a decrease in the urinary excretion of this element. When supplements of both calcium and phosphorus were added to the basal diet, calcium retention was somewhat greater than on the unsupplemented basal diet but was very much less than when the basal diet was supplemented with calcium alone. Phosphorus retention, on the other hand, was not influenced by these changes in calcium and phosphorus intake. Within the limits of the calcium and phosphorus intake levels employed in this investigation, the amount of phosphorus in the diet would appear to be a factor of considerable importance in determining calcium utilization in adult subjects.

Mineral Balance Studies on Poultry

1. From the results of calcium and phosphorus balances on laying pullets, it is shown that the pullets displayed a diminution of the calcium and phosphorus in their droppings over a period of about 2–3 weeks before laying, and a correspondingly increasing retention of these elements.2. Egg laying was correlated with a relatively heavy voiding of phosphorus in the droppings, involving a temporary negative phosphorus balance. This confirms and amplifies the results of other workers on this subject. The nature and meaning of the phenomenon are discussed.

STUDIES ON THE MINERAL METABOLISM DURING PREGNANCY AND LACTATION AND ITS BEARING ON THE DISPOSITION TO RICKETS AND DENTAL CARIES

STUDIES ON THE MINERAL METABOLISM DURING PREGNANCY AND LACTATION AND ITS BEARING ON THE DISPOSITION TO RICKETS AND DENTAL CARIES

EXPERIMENTAL RICKETS

SummaryDuring the investigations regarding experimental rickets it was found that:1)Owing to the lack of both Vitamin C and D in the dietthere is a negative phosphorus balance and a weak positive calcium balance turning negative.2) When Vitamin C only is lacking in the diet the calcium balance is poorer than with the addition of lemon juice.It is therefore not improbable that when dogs. at an early stage are put on a diet lacking Vitamin C they can be afflicted by scurvy or by a scurvy‐like condition, a disease in dogs where the changes undergone in metabolism have not hitherto been investigated.Cod‐liver oil cures experimental rickets very rapidly, both chemically and clinically. The negative or weak positive balances quickly become strongly positive.3) When Vitamin D is lacking in the diet:a) thus a form of rickets proper in dogs, a positive phosphorus balance and a negative calcium balance is found.b) Na2HPO4 added extra to the diet gives rise to clinically worse rickets but to a better phosphorus balance and parallel calcium balance than without the addition.c) Calcium lactate added extra to the diet gives rise to a clinically lesser pronounced rickets, with stronger calcium and phosphorus balances. Moreover, there is a greater calcium content in the bones.d) A salt mixture of Ca3(PO4)2, and CaCO3 (relationship 840:95) brings about greater calcium and phosphorus balances than without the addition of the salt mixture.e) Wheat‐flour, compared with oatmeal, produces clinically severer rickets, weaker phosphorus and magnesium balances but a stronger calcium balance.f) According to the balances of the elements concerned, the amount of calcium and inorganic phosphorus in the serum is lowered, in some cases very considerably.4) The magnesium balance is independent of both the calcium and phosphorus balances.5) The best balance of an element gives as a rule the greatest content of that element in the bones.6) On a diet which is extremely insufficient for a growing organism, oatmeal only, a diet deficient in Vitamin D and in Nitrogen in particular, a much stronger rickets is produced with negative calcium, phosphorus and magnesium balances.

The Physiological Effect of Rations Restricted Principally or Solely to the Alfalfa Plant: I. The Calcium, Phosphorus and Nitrogen Metabolism of Dairy Cattle

Summary We have reported a series of metabolism studies in which the nitrogen, calcium and phosphorus balances of dairy cattle were determine for 12 ten-day periods, during which the daily milk yields varied from approximately 9 to 18 kgm. The rations fed consisted of alfalfa hay with and without supplements of starch, linseed oil meal, or di-sodium phosphate. According to our data, cows in the early lactation period were usually in positive calcium balance; in negative nitrogen balance when the hay contained less than 2.0 per cent nitrogen; and always in negative phosphorus balance when only alfalfa hay was fed. Feeding di-sodium phosphate changed the negative phosphorus balances to slightly positive balances. We have also included a general discussion of some of the factors which may be involved in rations restricted principally or solely to alfafa.