Chapter XIII 



MISCELLANEOUS WATER-SOLUBLE 

 GROWTH FACTORS 



I. INTRODUCTION 



There is no reason to believe that membership of the vitamin B 

 complex is restricted to the compounds described in the preceding 

 chapters, although it is doubtful if substances of such outstanding 

 nutritional and therapeutic importance as aneurine and nicotinic 

 acid remain to be discovered. This is perhaps a sweeping and 

 unwise generalisation to make, but it appears to be warranted by- 

 evidence from clinical tests and animal experiments that the most 

 serious symptoms of vitamin B complex deficiency are more or 

 less completely relieved by aneurine, nicotinic acid and ribo- 

 flavine. 



For example, Elsom et al} studied the clinical effects of a deficiency 

 of the whole vitamin B complex and observed that many of the 

 symptoms, including anorexia and mental symptoms, were improved 

 by administration of aneurine alone, although other symptoms, such 

 as delayed motility of the small intestine, a macrocytic anaemia and 

 oedema of the upper and lower extremities, were not affected by either 

 aneurine or riboflavine, but were relieved by administration of yeast. 

 It is probable that many of these symptoms could have been relieved 

 by other members of the vitamin B complex had these been available 

 in 1940 when the work was carried out. From this point of view the 

 results of Keys et al.,^ carried out in 1945, are perhaps of greater signi- 

 ficance. They maintained eight normal young men on a diet pro- 

 viding 33,000 cals. and 75 g. of protein a day together with 0-18 mg. 

 of aneurine, 0-25 mg. of riboflavine and 3-5 mg. of nicotinic acid per 

 1000 cals. Another four men were given in addition i mg. of aneurine, 

 I mg. of riboflavine and 10 mg. of nicotinamide daily. The only 

 difference between the two groups after 161 days was that the first 

 had a slightly higher concentration of pyruvic acid in the blood than 

 the second group. At the end of this time, two men from the first 

 group were given a diet containing negligible amounts of all three B 

 vitamins ; they showed increasing anorexia from the seventh to the 



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