NUTRITIVE VALUE OF FISH AND SHELLFISH 547 



glands to produce tears. The eyes become dry and suffer profound 

 injury as a result of this and of bacterial infection. The salivary 

 glands are likewise affected, losing their capacity to secrete saliva. 

 The nose and ears become filled with a purulent discharge. These 

 are the most prominent effects of vitamin A deficiency. 



Vitamin B is most abundant in natural foods. All ordinary foods 

 used in America, except white flour, polished rice, degerminated 

 corn meal, sugar, starch, and the fats and oils, contain more or less 

 of the vitamin B. All lean meats are very poor sources of it, but 

 liver, kidney, and other glandular organs are excellent sources of it. 



Vitamin C is found in appreciable amounts only in fresh, raw 

 foods, especially in fruits and vegetables. The citrous fruits are 

 especially valuable in tliis respect. 



Vitamin D is especially interesting in that it is contained in very 

 small amounts in any foods thus far studied, except in the oils of 

 fishes. Many foods of both animal and vegetable origin are appar- 

 ently entirely lacking in it. The leaves of edible plants contain 

 small amounts of it, at least in certain cases. Cereals, tubers, root 

 vegetables, lean meats, ordinary animal and vegetable fats, fruits, 

 etc., are entirely lacking in this remarkable nutrient principle. 

 Vitamin D is especially important in the diet for the purpose of 

 insuring the normal development of the bones. The condition 

 which results from starvation for this vitamin (when the diet is 

 not properly constituted with respect to certain other nutrients, 

 especially calcium and phosphorus) is generally designated as rickets. 

 It is not confined to the bones, but affects all the tissues of the body 

 and may result in profound damage to health. Curiously enough, 

 while the vitamin D is very abundant in certain fish oils it is appar- 

 ently entirely lacking in the liver fats and in the other fats of the 

 bodies of mammals, such as beef, pork, etc. 



The A^tamin E is concerned with the reproduction. It, like the 

 vitamins A and D, is soluble in fats and oils and is found in certain 

 of these. It is especially abundant in the oil from the germ of wheat. 

 It is said to be absent from cod-liver oil and is certainly not abundant 

 in the ordinary fats that are rich in vitamin A, such as butterfat, 

 cod-liver oil, etc. 



Ail fats and oils from fish or other marine animals whenever ex- 

 amined have been found to be rich in vitamin A. Oil from herring, 

 shark liver, and cod liver are examples, the liver oils being especially 

 rich. Whale oil and seal oil are likewise rich in vitamin A, probably 

 because their food is rich in it. Lesser amounts of the vitamin have 

 been found in the oils from salmon and menhaden. It seems probable 

 that the fats in the flesh as well as in the livers of all marine animals 

 are rich in vitamin A. It has been the custom for centuries in 

 Japan to give eel fat to children who were suffering from lack of 

 vitamin A. This disease was so common among children that it 

 was well known as hiJcan. It is interesting that eel fat, like cod- 

 liver oil, should have been discovered as a result of common experi- 

 ence to have therapeutic value and for very different conditions. 



Herring and cod roe are the only roes that have been studied. 

 These are found to contain vitamin A, probably in as large amount as 

 do eggs generally. 



It is said tliat vitamin B is lacking in codfisli muscle and salmon 

 muscle, but that the vitamin is present in the entire body of the 



