METABOLISM AND TRANSPORT IN ANIMALS 



525 



and inflammation of the cornea of the eye. 

 This vitamin is contained in milk, green and 

 leafy vegetables, egg white, liver, meat, and 

 yeast. 



Vitamin Niacin (Antipellagric 

 Vitamin, P.P.-C6H5NO2) 



This constituent of the B complex pro- 

 tects against the disease known as pellagra, 

 which is characterized by roughened skin 

 on the hands, arms, feet, face, and neck, a 

 sore mouth, pink tongue, diarrhea, and nerv- 

 ous disturbances. Its richest source is brew- 

 er's yeast, but it is also present in wheat 

 germ, rice polishings, lean meat, milk, green 

 vegetables, peas, and beans. Niacin is a con- 

 stituent of certain coenzymes necessary for 

 cellular functions. 



Vitamin Pyridoxine (Vitamin 

 Be-CsHiiNOsHCl) 



Although no deficiency disease for man 

 has been identified, this vitamin has been 

 shown essential for his health. It plays an 

 important role in certain enzyme reactions 

 in amino acid metabolism in the cell. It 

 was first found to prevent dermatitis in 

 rats. Yeast, whole cereal grains, milk, and 

 liver are good food sources for Be. 



Pantothenic Acid (C9H17NO5) 



This vitamin is so widely distributed in 

 foods eaten by man that apparently he gets 

 enough; no deficiency disease is known in 

 the human species. A deficiency, however, 

 causes dermatitis in chicks; decreased 

 adrenal cortex function in rats; and diarrhea 

 and nerve degeneration in swine. 



Pantothenic acid contributes to the forma- 

 tion of an important chemical compound 

 known as coenzyme A. This coenzyme takes 

 part in the metabolism of carbohydrates, 

 lipids, and proteins. Yeast, cane molasses, 

 meat, egg yolks, milk, and liver are some of 

 the sources of this vitamin. 



Vitamin Folic Acid 

 (Vitamin M-CioHioNiOe) 



Deficiency produces anemia and sprue in 

 man. This vitamin is contained in green 

 leaves, soy beans, yeast, and egg yolk. 



Vitamin Biotin (Vitamin 

 H-C10H16N2O3S) 



This vitamin is necessary for the growth 

 of birds, but in man it is not a dietary re- 

 quirement for it is supplied by the intestinal 

 bacteria. Deficiency symptoms are diarrhea, 

 dermatitis, and nervous disorders. Sources 

 for this vitamin are liver, kidney, and yeast. 



Vitamin B12 (Cyanocobalamin— 

 C64H92N14O13PC0) 



Vitamin B12, the antipernicious anemia 

 vitamin that was first isolated from liver, is 

 necessary for the formation of red corpus- 

 cles. A deficiency in man causes pernicious 

 anemia. B12 is also essential for the growth 

 of young animals. Sources of this vitamin are 

 milk, liver, kidney, and lean meat. 



Vitamin C (Ascorbic 

 Acid-CeHsOe) 



The principal role of vitamin C is pre- 

 vention of scurvy, a disease due to the break- 

 ing down of capillaries resulting in loosened 

 teeth, bleeding gums, and fragile bones. The 

 conquest of scurvy is one of the 10 greatest 

 advances in medicine as listed in 1955 by 

 Dr. L.H. Roddis. Ascorbic acid was isolated 

 in pure form in 1932. It is present in citrus 

 fruits, and tomatoes. Animals, except pri- 

 mates and guinea pigs, produce vitamin C. 



Vitamin D (Antirachitic 

 Vitamin— Calciferol— C28H44O) 



Rickets is a disease involving softening of 

 the bones, leading to deformities (Fig. 



