VITAMINS 



163 



perimental animals. "We possess only two 

 experimental animals in which scurvy can 

 readily be produced: the guinea pig and 

 the monkey. What is there specific and 

 common about these two animals? The 

 answer can easily be found; these are the 

 two experimental animals which come from 

 the ever-green tropical surroundings where 

 there is green food (which contains ascorbic 

 acid) all year round. One of the basic laws 

 of Nature is laziness; Nature will not do 

 unnecessary things, and if a species has no 

 need to make ascorbic acid, it will not make 

 it; it will forget, or never learn how to 

 make it. The rabbit cannot permit itself 

 to do this, for it would die during the long 

 winter in our moderate climate. 



So you see the ability or inability to make 

 ascorbic acid, perhaps the most classical 

 vitamin, does not reside in some funda- 

 mental quality of the molecule or of the 

 animal. It lies in an accidental circum- 

 stance, in the living habits of the race in 

 question. To sum up our whole discussion, 

 we can say that vitamins do not represent 

 a specific group of substances, connected 

 and characterized by some basic quality of 

 their molecule. They are substances re- 

 lated by some accidental factor, like the 

 Pitamins. The word Vitamin has no deep 

 meaning; it does not convey much to the 

 mind. 



I do not want to belittle the practical im- 

 portance of Vitamins, for after all, we be- 

 come ill if we do not eat them, and we all 

 want to be healthy; so this is, at least 

 practically, a most important point. As 

 the whole importance of vitamins is con- 

 nected with this question of health and 

 disease, let me devote the rest of my time 

 to this problem. Again this practical, 

 medical application centers around one 

 question: how much of these vitamins 

 should we eat daily to keep fit? I fully 

 realize that this is not a medical conference. 

 But I can formulate this problem also in 

 more general biological terms and ask how 

 much of these vitamins an organism needs 

 for its normal function ? Had I been asked 

 this question two years ago I should have 

 answered with precision, giving the quanti- 



ties of the single vitamins in milligrams. 

 The great progress in this field is our 

 understanding that we are unable to an- 

 swer this question any more. 



To see this point better, let us watch the 

 vitaminologist for a moment at his work. 

 "We will watch a C-Vitaminologist. He will 

 take several, perhaps a dozen, guinea pigs 

 and put them on a C-free diet. To differ- 

 ent animals he will give different amounts 

 of ascorbic acid. He will observe that the 

 animals with no ascorbic acid die from 

 scurvy ; that animals with 0.5 mg daily show 

 mild scurvy; and that those with 1.5 mg 

 show no scurvy at all. He will be satisfied 

 and will say that those with 1.5 mg have no 

 scurvy, and are therefore healthy, and that 

 1.5 mg is thus the normal daily dose. 



This experience has been extended un- 

 consciously to man. Under ordinary con- 

 ditions we see no scurvy (and no beriberi 

 or pellagra), and we assume that there are 

 enough vitamins in our food. 



All this would have remained unques- 

 tioned had the biochemist not synthesized 

 vitamins and given them to the doctor, who 

 could now give unlimited quantities to his 

 patients. These trials have given unex- 

 pected results. To quote one example; it 

 has been found that alcoholic neuritis can 

 be cured by the application of vitamin Bi. 

 The special beauty of this is that we can 

 even go on drinking if we only take a little 

 Bi alongside. But how can we explain this 

 effect? "We have been told that there was 

 no lack of vitamin. Should we suppose 

 that the vitamin acted like aspirin, a chemo- 

 therapeutic agent which will give the 

 greater effect the more we take of it. This 

 would be in contradiction to our classical 

 conceptions. I must make this clearer : we 

 have seen that Bi is a co-decarboxylase. 

 Every day we must decarboxylate a certain 

 number of pyruvic acid molecules. For 

 this we need a certain number of Bi mole- 

 cules. If we have this number all is well, 

 for enough is enough. An excess will not 

 help. So we always supposed that most 

 vitamins produced a favorable effect only 

 if there was a shortage, and that an excess 

 would have no action, especially in the case 



