VITAMINES.*
UNDER the title Vitamins Dr. Benjamin Harrow, of Columbia University, writes a very useful little book, in which he introduces the study of what is known of the above-named mysterious elements in food, by eight chapters dealing with food values in general. It was the lot of the present writer during the war to try to give some exceedingly elementary explanations of food values to entirely uninstructed audiences, and this handbook would have been of infinite use as stating, in a manner which could be understood by anyone, those elementary facts which Are required in order to arrange a properly balanced diet. For instance, Dr. Harrow's description of the nitrogen equilibrium could be grasped by the most limited intelligence. Although the chapters which he devotes to the description of research in the main portion of his book are moat informing, ordinary people would get as much information as they need out of the memorandum issued by the British Committee on Accessory Food Factors in 1919, which is printed as an appendix. Here the division of vitamins into three factors—anti-neuritic, anti-rachitic, and anti-scorbutic—is clearly given, and the uses of the various vitamins are indicated. The anti-neuritic factor is apparently that which lies in the germ and husk of cereals and grains, such as rice. It is held so necessary as a preventive of beri-beri that its alternative name is the anti-beri-beri Factor. The anti-rachitio factor is what is necessary to promote growth and prevent rickets in young animals. It is present in certain animal fats, such as butter and the yolks of eggs, and it is also present in a, limited extent in the vegetable world. The tomato, for instance, contains it, but in vegetable oils—linseed nil, olive oil, coco- nut oil, &c.—it is only present in negligible quantities. Lard —contrary to one's expectations—is also deficient in this factor, though in beef fat and fish oils it is present in sufficient quantities. The anti-scorbutio factor is found in fresh fruit and vegetables. Lemons and oranges contain it, but lime-juice is inferior in value. Dried foodstuffs are deficient in thin principle, but in the case of dried beans, if they are put into water and allowed to sprout, the factor appears to return to the bean. This is why we were all told during the war not • Vitamins: Essential Food Factors. By Benjamin Renew. London. Boutledge. Roe. ed. net.
only to soak haricot beans before using them for food, but to keep them in the kitchen cupboard. till they sprouted.
The whole history of vitamines is so mysterious, and our knowledge so imperfect, that it is impossible to help feeling that further discovery may either reverse or enlarge the conclusions come to in this volume. Consider I No one, if we understand Dr. Harrow aright, has ever seen a vitamin, and its presence or absence is only deduced by experi- ment. The actual name was invented to describe the " some- things " or substances, call them what we like, which, to quote Dr. Harrow, " though present in minute quantities in foods, are absolutely essential to a continuation of the life process."
The presence or absence of these vitamines is as great a factor in the proper balancing of diets as the due proportion of proteins, carbohydrates, and fats. The ordinary mixed diet of the earlier part of this century from its very variety and extent provides a sufficiency of these essential substances, but, as Dr. Harrow very properly observes :-
" aside from supplying us with a raison d'ftre, studies in the science of nutrition are helping to avert the food famine which, in these days, constantly hovers over us. . . . to-day, with our limited food supply, we can no longer afford to be prodigal. Unless the essential factors in diet are known, and unless such knowledge is put into practice, we shall suffer from deficiency diseases even more than our forefathers."
Those who without scientific training have to arrange for the diets of a number of people cannot do better than study Dr.
Harrow's book, in which in the earlier chapters they will find an excellent guide to the better-known ingredients necessary in considering food values, while the latter half will give them an appreciation of all that is known of these mysterious substances, which, though unseen and unmeasured, are the real foundation of our physical well-being.
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