114 O. J. Malm, R. Nicola ysen and L. Skjelkvale 



As a result, we introduced oxalate as a Ca "trapper". 



It needs emphasis, that the lack of adaptation of tlie 

 absorption in rats is in reality nothing but a confirmation 

 of the principle which can be extracted from all earlier 

 observations in vitamin D deficiency in man, not least from 

 results in late rickets and in osteomalacia (see Nicolaysen 

 and Eeg-Larsen, 1953, for the metabolic pattern). 



Experiments in Men 



These were long term balance experiments conducted in 

 our main prison. Only several consecutive two- week periods 

 were used for calculations, and all observations were based 

 on analyses of food as served and eaten. The procedure was 

 that any person taken for experiment was first observed for 

 a period ranging from some months to a year on the level of 

 Ca intake of about 900 mg. daily. When the Ca "charac- 

 teristic" of a given person had thus been established at this 

 level, the Ca intake was reduced. The vitamin D intake was 

 at least 200 i.u. daily. 



Results 



In all thirty-eight men were studied. However, some were 

 released before an adaptation experiment could be conducted 

 over a sufficient period of time. Therefore only twenty-five 

 out of the thirty-eight were subjected to such a procedure. 



In Fig. 3 the balances of all thirty-eight men have been 

 given, and in Table I are condensed and summarized the results 

 of the adaptation study in twenty-five men. In Fig. 3 the 

 figures have been arranged according to age, whereas in Table 

 I they are according to increased, calculated requirement. 



Most of the men were overweight according to the Metro- 

 politan Insurance Company's standard table which was 

 used for correction. 



The figures for urine and faecal Ca are given with their 

 standard errors. In some the variations were irregular, but 

 in other persons long waves in the faecal Ca output occurred 

 at one level of intake. A definite trend of the curves for 



