Experiments upon the total metabolism of iron and calcium in man

Abstract

Each of the experiments was of three days duration and the same healthy man served as subject throughout. On a diet of crackers and milk, which furnished 0.0057 gram iron and 2.65 grams calcium oxide (Exp. I), there was equilibrium with respect to iron, and a storage of calcium. When the diet consisted of crackers and egg-white with 0.0065 gram iron and 0.14 gram lime (Exp. II), or of crackers alone with 0.0071 gram iron and 0.13 gram lime (Exp. III), there were losses of both iron and calcium. These losses occurred through the intestine, but were evidently not due to intestinal putrefaction, since the ratio of sulphur in ethereal to that in simple sulphates in the urine was determined in Exp. Ill and found to be as 1:25. The results appear to confirm the suggestion of Von Wendt that a deficiency of calcium in the diet may lead to a loss of iron as well as of calcium from the body. There was a slight tendency toward diarrhea in each of the periods in which loss of iron and calcium occurred. The iron requirement evidently varied greatly, the average daily output for three experiments being 5.5, 8.7 and 12.6 milligrams respectively.

The lime requirement was found by further experiments (IV and V) to be about 0.75 gram of calcium oxide per day.

The experiments were conducted at Columbia University in coöperation with the U. S. Department of Agriculture and will be described in detail in a bulletin of the Office of Experiment Stations of that department.