Am.  Jour.  Pharm. 
May,  1914. 
The  Vitamines. 
237 
THE  VITAMINES.1 
The  Recognition  oe  Essential  Constituents  of  the  Diet 
Hitherto  Unclassified — Deficiency  Diseases. 
By  Percy  G.  Stiles. 
If  a  physiologist  is  asked  what  are  the  requisites  of  a  normal  diet 
he  will  probably  reply  somewhat  as  follows :  First,  it  must  represent 
an  adequate  quantity  of  available  potential  energy,  not  less  than 
2,000  calories  for  the  average  human  adult.  Second,  it  must  contain' 
protein  (nitrogenous)  food  sufficient  to  compensate  for  the  un- 
avoidable daily  loss  of  similar  material  from  the  body.  Third,  it 
must  be  palatable  and  digestible,  making  due  allowance  for  personal 
idiosyncrasy.  He  will  very  probably  content  himself  with  these 
three  postulates. 
If  the  inquiry  is  pressed  the  man  of  science  may  recollect  that 
another  necessary  condition  of  successful  nutrition  is  a  proper 
supply  of  the  inorganic  or  mineral  elements  in  sufficiently  varied 
assortment.  The  tissues  cannot  be  developed  or  maintained  without 
chlorides,  phosphates,  and  other  saline  contributions.  The  need  for 
substances  of  this  class  is  more  urgent  during  the  period  of  growth 
than  later,  but  it  always  continues  to  exist.  A  similar  statement  may 
be  made  with  reference  to  the  protein  of  the  ration ;  this,  too,  must 
be  furnished  in  relative  abundance  and  varied  form  during  the 
growth  of  the  subject  and  may  be  reduced  when  full  stature  has 
been  reached.  Mendel  has  shown  that  kind  as  well  as  quantity 
must  be  considered  when  protein  is  chosen  for  experimental  nutri- 
tion of  an  animal.  Proteins  from  certain  sources  suffice  for  main- 
tenance only  and  not  to  minister  to  growth. 
With  the  accumulation  of  physiological  data  during  the  past 
few  years  it  has  become  increasingly  apparent  that  there  may  be 
criteria  for  the  adequacy  of  a  diet  not  included  in  the  list  just  given. 
There  are  now  known  to  be  organic  compounds  other  than  proteins, 
small  quantities  of  which  are  absolutely  essential  to  normal  growth 
and  even  to  continued  health  in  the  adult  condition.  The  name  of 
Vitamines  has  been  proposed  for  all  such  substances.  The  word 
is  well  chosen  in  view  of  its  root-meaning ;  an  amine  is  a  nitrogenous 
compound  of  a  certain  type  and  a  vitamine  is  obviously  such  a 
1  Reprinted  from  Science  Conspectus,  Vol.  IV,  1914,  pp.  10-13. 
