ANIMAL AND HUMAN REQUIREMENTS 



deficiency, whence it was concluded that the minimum intake to main- 

 tain health was 0-65 mg. per day. 



Saturation tests were used by D. Melnick,^ who stated that adults 

 required 0-35 mg. of aneurine per 1000 cals. or 0-875 mg. per day, 

 assuming a calorie intake of 2500 cals. per day. He recommended a 

 minimum intake of 0-5 mg. per 1000 cals., however. Of the subjects 

 tested (Americans) only 73 % excreted sufficient aneurine to pass all 

 clearance tests. Saturation tests were also employed by R. D. Williams 

 et al.'^^ who found that an intake of o-i to 0-175 mg. of aneurine per 

 1000 cals. caused a rapid, and one of 0-22 mg. per 1000 cals. a slow, 

 depletion of the tissue reserves, whereas an intake of 0-45 mg. per 

 1000 cals. was associated with only a slight depletion of cocarboxylase. 

 H. Oldham et al.^^ found that 0-5 mg. per 1000 cals. satisfied the 

 aneurine requirements of adults. 



As an example of the third type of investigation, the results of 

 T. Moran and R. G. Booth ^^ may be cited. After carrying out a 

 dietary survey, they concluded that 50 % of the population of Britain 

 in the early days of the 1939-45 war had an inadequate intake of the 

 vitamin ; they gave the average requirement of the population as a 

 whole as 2-3 mg. per day on a diet supplying 2810 cals. per day ; 

 this is equivalent to 2-05 mg. per 2500 cals. Excluding lactating 

 women and young children, the aneurine requirement was estimated 

 at 1-4 mg. per day or 1-25 mg. per 2500 cals., a value identical with 

 the intake recommended by Melnick. M. D. Wright, ^^ however, 

 considered this value to be inadequate, and stated that 1-9 mg. per 

 day should be regarded as the minimum. E. G. Young ^* made a 

 dietary survey among Canadian families with incomes ranging from 

 $450 to $1500 per annum, and found that the average consumption 

 of aneurine was 0-20 mg. per 1000 cals. for men, 0-19 mg. per 1000 

 cals. for women and 0-22 mg. per 1000 cals. for children, considerably 

 lower values than those generally accepted as desirable. Yet no 

 evidence of clinical aneurine deficiency was observed. 



Lane et al.^^ stated that, prior to the introduction of enriched flour, 

 the average vitamin B^ content of the American diet — due in the main 

 to lean pork, bread and milk — was 0-8 mg. per 2500 cals., amuchlower 

 figure than the minimum standard suggested by Melnick and by W'right. 

 The use of enriched flour increased the value to 1-3 mg. per 2500 cals., 

 a figure just above Melnick's minimum, but below W^right's. 



On the whole, there is a surprising unanimity about the minimum 

 human requirement for aneurine, and we may safely assert that at 

 least 1-25 mg. per 2500 cals. should be given in order to maintain 

 health. The optimal quantity, that is, the amount required to 

 ensure full activity, is probably much higher, probably in the region 

 of 2-5 mg. per 2500 cals. 



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