The excretion of vitamin A in urine.

SINCE vitamin A is insoluble in water one would not expect to find it in urine. As far as normal human urine is concerned this expectation appears to be correct. An early claim by Cooper [1924] to have detected vitamin A in human urine by biological means was criticized by Rowntree [1930], who could not confirm the presence of the vitamin in urine from children even when the diet contained milk, eggs, carrots and cod-liver oil. Kaufmann & Drigalski [1933] obtained negative results from human urine by colorimetric methods. In the urine of rats Davies & Moore [1934] found no vitamin A by the colorimetric method even when toxic overdoses of the vitamin were given. Przezdziecka [1935] claimed to have detected vitamin A in urine by a colorimetric method, which was, however, applied in so unusual a manner as to leave doubt as to the significance of the observation. In urine from pathological subjects, however, Boiler & Brunner [1936] obtained positive results by the SbCl3 method in 10 out of 42 cases examined. Half of the patients excreting the vitamin had cancer. Later, Boiler et al. [1937] published results on 321 cases. Vitamin A was found in the urine in icterus with closure of the biliary duct, chronic nephritis, nephrosis, lobar pneumonia before crisis and cirrhosis of the liver. Large oral doses of vitamin A had little effect on the amounts excreted in the urine. Excretion, was reduced by pyramidone. The presence of vitamin A in pathological urine was confirmed by Schneider & Weigand [1937, 1, 2]. Excretion was observed in cancer, tuberculosis and chronic infections. The excretion was not due to specific renal damage, nor was it caused by increased ingestion of the vitamin. It was claimed that excretion only took place in hypovitaminosis C, and that it could be checked by giving ascorbic acid. Lindqvist [1937] found that in pneumonia the excretion of vitamin A varied from 228 to 3060 I.u. xdaily before crisis, failing to zero after crisis. Urinary excretion was associated with a lowered vitamin A content of the blood, which returned to normal after crisis. Gaehtgens [1937] reported the presence of vitamin A in urine from 8 out of 31 cases ofnormal pregnancy. After large doses of vitamin A had been given it was found in the urine in 19 cases. In chronic nephritis Hedberg & Lindqvist [1938] observed constant or irregular excretion of vitamin A in 23 out of 25 cases. In contrast with the finding in pneumonia the vitamin A content of the blood was often high. In livers taken at autopsy the reserves were frequently low, but bore no relation to