[Effect of contraceptives on the digestibility of dietary protein and nitrogen balance]

The present paper deals with the effects of the hormonal contraceptives Deposiston and Gravistat on the digestibility of dietary crude protein and on the urine excretion of nitrogen. The substances under test were given to nine women aged between 18 and 25 years. The faecal and the urinary nitrogen were determined in the first two cycles during which no contraceptives were used, and also in the subsequent three cycles during which Deposiston and Gravistat were taken by mouth. The preperiod extended over 3 days; and the sampling period, over 4 days. The apparent digestibility of the dietary protein was but slightly increased by the contraceptives. In case of Deposiston for example, it amounted to 85.0% (1st cycle), 86.0% (2nd cycle), 87.3% (3rd cycle), 87.1% (4th cycle), and 88.2% (5th cycle). Deposiston and Gravistat did not affect the urine excretion of nitrogen and the nitrogen balance.