320 ATsnsnjAL report Smithsonian institution, 1941 



of lack of vitamins are usually expressed as to effects on human be- 

 ings or laboratory animals, the statements should be evaluated 

 accordingly. 



Vitamin A. — Known to exist in oil from cod, halibut, and certain 

 other fishes ; egg yolk, whole eggs, spinach, liver, raw carrots, cheese, 

 fresh prunes, squash, butter, sweet potatoes, green lettuce, cream, 

 peas, tomatoes, peaches, salmon, bananas, milk, yellow corn, and al- 

 falfa, arranged in the order of their richness in this vitamin. In 

 vegetables, vitamin A occurs as carotine and is known as provitamin 

 A. Lack of the proper supply of this vitamin is evidenced by eye 

 and skin defects, possible susceptibility to infections, and retarded 

 growth. 



This vitamin can be given to animals in the form of cod liver oil, 

 halibut liver oil, and several well-known medicinal concentrates. 

 The vitamin A value in cod liver oil is seriously impaired by expos- 

 ing the oil to light or heat, or when the oil becomes rancid. It 

 should be used sparingly because of injurious effects due to overdos- 

 age. Green plants eaten in sufficient quantities will ordinarily sup- 

 ply the animal with enough of this vitamin. Apparently all verte- 

 brate animals require this vitamin. Pregnant and nursing females 

 require unusual quantities. 



Vitamin B^ (thiamin hydrochloride). — Found in yeast, wheat 

 germ, rice polishings, whole-grain cereals, peanuts, dried beans, 

 liver, milk, nuts, malt, ham, bacon, almonds, spinach, prunes, pars- 

 nips, carrots, corn (canned), and greens, in order of the richness of 

 their content. 



Deficiencies in this vitamin in man are evidenced by lack or loss 

 of appetite, retarded growth of young, and increased nervous excit- 

 ability, pains, tremor, and muscular fatigue. 



Can be supplied in cod liA^er oil, halibut liver oil, commercial con- 

 centrates, capsules, and drop dosages. Thought to be required by 

 all animals, but it is Imown that ruminants manufacture this in their 

 digestive tracts. Others of the B group are also manufactured by 

 certain animals. 



This compound is readily destroyed by heat and alkalines. 



Vitamin B2 (riboflavin). — Good sources are dried yeast, liver, 

 kidney, eggs, meat, wheat germ, spinach, milk, cheese, milk whey, 

 turnip greens, carrots, and carrot tops, kale, and cottonseed. 



Deficiency in this vitamin is associated with digestive disturbances, 

 retarded growth, reduced lactation, loss of hair and other skin 

 troubles, eye diseases, and irritation of the gums and tongue. 



Can be supplied in commercial tablets. 



This compound is destroyed by strong light. 



Nicotinic acid and nicotinic acid amide. — Good sources are dried 

 or concentrated yeast, liver, lean meat, kidney, heart, buttermilk. 



