318 THE FOODS WE EAT 



But sooner or later, if we are careless, we pay the penalty, 

 sometimes in loss of "pep," sometimes in indigestion, or 

 during constipation, or even loss of weight and vitality. 

 The last few years science has made wonderful progress in 

 scientific discoveries about foods, and the most interest- 

 ing are those about the vitamins, substances which are 

 necessities for bodily growth and health. It has also been 

 proved that certain mineral substances found in milk, 

 water, and other foods are also necessary for health. Such 

 foods are called protective or regulative. It has taken a 

 good deal of experimentation, both with animals and man, 

 to learn all we have about these wonderful substances, 

 and we are finding out more every day. 



The Vitamins. The vitamins are called after letters of 

 the alphabet, A, B, C, D, E, and G. Vitamin A has been 

 found to aid us in resisting colds, pneumonia, tuberculosis, 

 sinus infections, and the like. It is a resistance-building 

 vitamin and also promotes growth. It was first dis- 

 covered when its absence caused an eye disease in rats 

 and other animals as well as interfering with the body 

 activities. Vitamin A is found abundantly in kale, spinach, 

 turnip greens, and other leafy vegetables, such as cabbage 

 and lettuce, in vegetables containing yellow pigment, 

 such as carrots and yellow corn, and in butter, oils, eggs, 

 and the fat of milk. 



Vitamin B also helps growth and seems to aid in build- 

 ing up the nervous system because its lack causes a nervous 

 disease called beri-beri. This disease is very prevalent 

 among people of the tropics whose diet consists largely of 

 rice. Vitamin B is found in vegetables, such as asparagus, 

 cabbage, wheat germs, and tomatoes ; in yeast and liver, 

 whole cereals, and milk. 



Vitamin C is most common in citrus fruits, such as 

 oranges and lemons, in many other fresh fruits, and in 

 milk, It helps the growth of bone and the teeth and 



