….are elsewhere considered in this booklet, hence only a very brief summary here. The chemistry of these products is very little understood at present. They were so named because vitamins were originally thought to contain amino acids ( the suffix -amins) which was later determined as false. The term ‘vital’ carries with it the idea of their importance to life. Some persons have questioned this name; but up to present, it seems to be best suggested.
The importance of the vitamins in nutrition has been very clearly demonstrated in experiments upon animals and these experiments have been repeated a sufficient number of times to be conclusive. Animals have been fed upon pure protein, fat, carbohydrate and salts, but the vitamin removed or destroyed; and although receiving calories enough, they fail to keep in their nutrition. With a simple change of dietary to include a small amount of food containing the vitamin, without any change in the total calorie eaten, their nutrition improves quickly and they come back to a normal state.
Foods rich in vitamins are represented by milk, fresh vegetables, fresh fruits and whole grain products. Foods poor in these substances are represented by sterilized and preserved milks, dried fruits, dried vegetables, white flour and polished rice. Vitamins are reduced or lost by the following process in the preparation of foods; taking off the coating of grain, overheating, washing out in cooking and drying.