XXXU CONTENTS 



XII. The Metabolism and Niitrilional Value of the Vitamins K 751 



1. Introduction 751 



2. The Occurrence of the Vitamins K 754 



(1) Occurrence in Plants 754 



(2) Occurrence in Microorganisms 755 



a. The Role of Vitamin K in Bacterial Growth 756 



I). The Effect of Antibiotics 756 



(3) Occurrence in Animals 756 



3. The Digestion and Absorption of the Vitamins K 757 



4. The Synthesis of Vitamin K in the Gastrointestinal Tract 759 



5. The Transport of Vitamin K from the Intestine to the Tissues . . 760 



6. The Physiologic Role of Vitamin K 761 



(1) The Importance in Blood Coagulation 761 



a. The Liver as the Site of Action of Vitamin K 762 



b. The Mechanism of Action of Vitamin K in Prothrombin Syn- 



thesis 763 



c. Vitamin K in Various T>T)es of Bleeding 764 



d. Various Factors Associated with Vitamin K and with the Clot- 



ting Mechanism 765 



(2) In Counteracting Hemorrhagic Conditions due to Dicumarol. . . . 766 



(3) Miscellaneous Effects of Vitamin K 771 



7. Vitamin K H^'jjovitaminosis 772 



(1) Methods of Producing Deficiency 772 



a. Dietary Lack of Vitamin K 772 



b. Inhibition of the Synthesis of Vitamin K in the Gastrointestinal 



Tract 773 



c. Reduced Absorption of Vitamin K 774 



d. The Importance of the Liver in Vitamin K Utilization 775 



(2) Symptoms of Avitaminosis K 776 



8. HjTDervitaminosis K 776 



9. Comparative Activity of Vitamin K- Active Compounds 778 



10. The Requirements for Vitamin K 779 



(1) Requirement for the Chick 779 



(2) Requirement for Other Animals 780 



(3) Requirement for Man 781 



XIII. The Physiology and Biochemistry of the Essential Fatty Acids 783 



1 . Introduction 783 



2. Chemical Relations of Polyunsaturated Fatty Acids 784 



( 1 ) Polyunsaturated Acids Having Biologic Importance 784 



(2) Methods of Preparation of Polyunsaturated Acids 786 



a. Introduction 786 



b. Low-Temperature Crj'stallization 786 



c. The Urea-Adduct Method 787 



d. Preparation from Bromo-Derivatives 788 



e. Chromatographic and Related Methods 788 



