Effects on Ca and P Metabolism in Humans by Adding Meat, Meat Plus Milk, or Purified Proteins Plus Ca and P to a Low Protein Diet

Abstract
The effects on calcium and phosphorus metabolism of adult man by adding meat or meat plus dairy products to a diet low in protein (55 g), calcium (590 mg), and phosphorus (890 mg) were determined. When the low protein diet was consumed, the subjects retained a mean of 20 mg calcium daily but lost 106 mg phosphorus. The addition of meat which increased protein and phosphorus to 146 g and 1660 mg, respectively, caused calcium retention to decrease from 19 to -17 mg but phosphorus retention to increase from 106 to 55 mg. When the meat plus dairy diet high in protein (146 g), calcium (1370 mg), and phosphorus (2060 mg) was consumed the subjects retained substantial amounts of calcium (101 mg) and phosphorus (177 mg). The simulated diets high in purified proteins and supplemented with calcium and phosphorus affected calcium retention in manner similar to the meat and meat plus dairy diets, but they had a marked negative effect on phosphorus retention; this indicates that supplements of calcium gluconate were well utilized but that those of monopotassium phosphate were not. The results obtained on urinary sulfate, acid, cyclic AMP and hydroxyproline support the conclusions made from the calcium and phosphorus data.