VITAMINS 361 



animals concerned. All higher animals probably rc(jiiirc this \itamiii, 

 but under normal conditions intestinal synthesis is adecjuatc even 

 if the diet is not. Daily allowances cannot be recommended at present. 



Deficiencies can be produced on laboratory diets which include 

 sulfa drugs and the like to prevent vitamin synthesis in the intestine. 

 Spontaneous subcutaneous hemorrhages are observed and prolonged 

 or fatal bleeding results from minor injuries. 



In man the pathologies that interfere with the intestinal absorption 

 of lipides lead to vitamin K deficiency. These include obstruction of 

 the bile duct or intestine, failure of the pancreas, and the disease 

 sprue. Surgical remedies, where possible for these conditions, require 

 prior use of a suitable drug to prevent death from hemorrhages during 

 the operations. 



Both internal and external bleeding is observed in about 10 per cent 

 of newborn children and persists for 2 to 6 days without vitamin 

 treatment. This sometimes serious problem is due to lack of a suitable 

 intestinal flora and consequent vitamin K deficiency. Reduced bleed- 

 ing of the mother during delivery is reported when K is given before 

 or at the onset of labor. Such treatment also supplies enough of the 

 vitamin to the infant to allow time for the formation of a normal 

 flora. 



Cattle on sweet-clover pastines are subject to sweet-clover disease, a 

 typical vitamin K deficiency due to the occurrence of a natural 

 antagonist for the vitamin in the plant. This antivitamin is used 

 medically in the prevention of blood clots where there is danger of 

 thrombosis, especially during certain stn-gical procedures. The dosage 

 is rather critical since too much induces hemorrhaging. The anti- 

 vitamin is called dicoumarol. 



CHo 



OH OH 



dicoumarol 



VITAMIN ASSAYS 



Many kinds of methods are used in the estimation of the various 

 vitamins found in different foods and feeds. The development of 

 accurate determinations is not as simple as might at first appear. The 

 great complexity of the materials to be examined makes likely the 



