330 IV. DIGESTION OF LIPIDS OTHER THAN FATS 



relationship of bile to vitamin K absorption has been excellently reviewed 

 by Almquist. 535 



The production of a vitamin K deficiency is accelerated in mice 536 and 

 in rats 537,538 by the feeding of mineral oil. Javert and Maeri 539 reported 

 that the prothrombin time is also increased in human subjects after the 

 administration of petroleum oil. The effect of mineral oil is apparently 

 not confined to the removal of the exogenous vitamin K from the gastro- 

 intestinal tract; it must also prevent the absorption of the endogenous 

 vitamin K which is constantly being synthesized by the intestinal bacteria. 



b. The Synthesis of Vitamin K_> in the Gastrointestinal Tract. It was 

 proved that the antihemorrhagic tendency of foods depends to a marked 

 extent upon bacterial spoilage, 540541 and that the droppings of vitamin K- 

 deficient chicks also contain a similar antihemorrhagic substance. 542 It 

 has also been shown that vitamin K is present in many bacteria, including 

 the water microbe, Bacillus cereus and the "hay bacillus" from air, water, 

 and soil, B. subtilis. bi3 The vitamin K synthesized by bacteria differs 

 slightly from that produced in plants; it is 2-methyl-3-difarnesyl-l,4- 

 naphthoquinone, and is referred to as vitamin K 2 . Vitamin K h which is 

 present in plants, is 2-methyl-3-phytyl-l,4-naphthoquinone. Vitamin 

 K 2 has a biopotency slightly less than that of vitamin Ki; the entire dif- 

 ference can be accounted for by its somewhat higher molecular weight. 



Intestinal bacteria of most higher animals can synthesize vitamin K 2 

 readily. Not only has the presence of vitamin K been demonstrated in 

 chick feces, 542 but also this vitamin has been reported in human feces. 534 - 544 ' 545 

 McElroy and Goss 546 likewise proved the presence of vitamin K in the 

 rumen of the cow, even when the animal was receiving a vitamin K-free 

 diet. 



535 H. J. Almquist, Physiol. Revs, 21, 194-216 (1941). 



536 W. A. Barnes, Proc. Soc. Exptl. Biol. Med., 49, 15-19 (1942). 



537 M. C. Elliott, B. Isaacs, and A. C. Ivy, Proc Soc. Exptl. Biol. Med., 43, 240-245 

 (1940). 



538 E. K. Bacon, S. Lassen, S. M. Greenberg, J. W. Mehl, and H. J. Deuel, Jr., ./. Nutri- 

 tion, 47, 383-398(1952). 



539 C. T. Javert and C. Macri, Am, J. Obstet. Gynecol, 42, 409-414 (1941). 

 640 H. J. Almquist and E. L. R. Stokstad, Nature, 136, 31 (1935). 



541 H. J. Almquist and E. L. R. Stokstad, ./. Biol. Chem., Ill, 105-113 (1935). 



542 H. J. Almquist and E. L. R. Stokstad, J. Nutrition, 12, 329-335 (1936). 



543 H. J. Almquist, C. F. Pentler, and E. Mecchi, Proc. Soc. Exptl, Biol Mel, 38, 336- 

 338 (1938). 



544 H. Dam, Angew. Chem,, 50, 807-811 (1937). 



845 E. M. Nelson and C. D. Tolle, Ann. Rev. Biochem., 8, 415-434 (1939). 

 546 L. W. McElroy and H. Goss, /. Nutrition, 20, 527-540 (1940). 



