222 VITAMINS 



SO slow that the rats do not become "bait-shy" and that higher animals 

 are proportionately less sensitive to it than are rodents. 



0=C-CH3 

 ^ I 



O f= 



L2 



H I c H 



H H 



"Warfarin" 



Occurrence 



Vitamin K is particularly concentrated in green tissues of plants. Al- 

 falfa, kale, spinach, carrot tops, chestnut leaves, and oat sprouts are 

 some of the most potent sources of the vitamin. It also occurs in soy- 

 bean and other vegetable oils. Cereals and seeds, however, are generally 

 poor sources. 



ASCORBIC ACID (VITAMIN C) 

 Physiological function 



A pronounced lack of vitamin C in the diet leads to a deficiency disease 

 known as scurvy. The onset is gradual and is characterized by loss of 

 weight, a sallow or pallid complexion, tendency to fatigue, and shortness 

 of breath. The gums become swollen, bleed easily, and ulcers may form. 

 In later stages the teeth loosen and may drop out. Hemorrhages into 

 the mucous membranes, skin, joints, limbs, and bone marrow, together 

 with fragility of the bones are noted upon autopsy. These hemorrhages 

 into the skin are quite obvious during life because blue-black spots occur 

 after trivial injury, or they may appear spontaneously. The joints be- 

 come swollen, and fleeting pains are noted in them. Death may eventu- 

 ally follow the headache, convulsions, and delirium that are seen in the 

 later stages, or it may be caused directly by such complications as heart 

 failure or pneumonia. Only two species other than man, namely, guinea 

 pigs and monkeys, have been found susceptible to scurvy. Other animals 

 seem to possess the power to synthesize vitamin C. However, the amount 



Plate III. Clinical symptoms of vitamin C deficiency (scurvy). A. Inflammation 

 and congestion about hair follicles. B. Petechiae (multiple small hemorrhages under 

 the skin) in a scorbutic patient after application of blood pressure cuff. Increased 

 pressure below the cuff has caused rupture of weakened capillaries. C. Purpura 

 (purple blotches caused by bleeding under the skin) in a scorbutic patient, from the 

 pressure of shoes. D. Purpura and petechiae in a scorbutic patient. E. Bleeding 

 gums in an infant with scurvy. F. Scorbutic gums in an adult. (Reproduced with 

 permission of Paul Hoeber, Inc., from Clinical Nutrition by Jolliffe, Tisdall, and 

 Cannon, New York, copyright 1950.) 



