418 



THE BIOCHEMISTRY OF B VITAMINS 



factor. There is generally an accompanying deficiency of the fat-soluble 

 vitamins due to faulty absorption, 134 - 135 together with nightblindness, 

 hypocalcemia and hypoprothrombinemia. 136 It differs from pernicious 

 anemia in the skin pigmentation, frequent presence of the intrinsic factor, 

 frequent occurrence before puberty, general presence of gastric acid, 

 absorption defects, and frequent association with poor diets. There is a 

 typically flat oral glucose curve, but a normal intravenous one, and no rise 

 in blood phosphate after oral glucose. Impaired glucose absorption in this 

 case has been interpreted as due to an impaired phosphorylation mecha- 

 nism in the intestinal wall, fructose absorption being apparently normal. 137 



FOUC ACIO 

 10,000 /tf. daily 



XS: 



i 1 1 i i i I 1 1 1 1 1 1 i 



i i i 1 1 i i i 



VITAMIN B„ 

 15/tf.lM. 



v/* 



I I 1 1 1 1 1 1 1 1 1 



I 1 1 1 1 II 1 1 1 1 1 1 I 



3579 II 13 13579 II 13 13579 It 13 

 DAYS 



Figure 20. Hematological response in a case of nutritional macrocytic anemia. 



Frequent classification into tropical and nontropical varieties seems justi- 

 fied only on the basis of its more frequent occurrence and severer forms 

 in the tropics. Sprue must be regarded as a multiple deficiency, initiated 

 perhaps by infectious conditions or general malnutrition, and propelled 

 by the diarrhea and other factors that make absorption inefficient and 

 create a vicious cycle. The symptoms generally respond well to liver 

 therapy and improved diet. The response of sprue to thymine, folic acid, 

 and vitamin Bi 2 , is almost identical with that of pernicious anemia, and 

 similar data from the Spies et al. study previously mentioned 124 is shown 

 for a case of tropical sprue in Figure 19. In separate studies, 138 it has 

 been shown that massive doses of thymine are followed by at least a 

 year of freedom from sprue and its symptoms. Pteroyldiglutamic and 



