1922 Encyclopædia Britannica/Vitamine
VITAMINE, the term now employed to designate certain substances contained in foods. The exact nature of these substances is not known, but they have been shown to be necessary to the normal development of young animals (including children) as well as to the maintenance of health and well-being in adults. They are very labile substances which, existing abundantly in raw foods, especially in uncooked fruits and vegetables, become seriously attenuated or altogether destroyed by cooking, desiccation, decortication and other refining processes. There are probably a great many vitamines in natural foods — live or quick foods, as they are called — but up to the time of writing three only have been isolated. These are (1) the anti-scorbutic factor; (2) the water-soluble B.; (3) the fat-soluble A.
The Anti-Scorbutic Factor. — As long ago as 1734 J. E. Bachstrom observed that the disease known as scorbutus or scurvy appeared to be related to the ingestion of salted, preserved and dried foods. The disease in question was alarmingly prevalent among mariners on long distance sailing vessels, and the British navy was annually decimated by this scourge. The introduction of fresh vegetables and fruits into the dietary of the sailors was found to afford them complete protection against the disease, but the knowledge thus empirically gained was not followed by any scientific investigation, and though the door was thus widely opened to the discovery of vitamines, these important substances were destined to lie perdu for nearly 200 years. This anti-scorbutic factor is the most fragile of the three which have so far been isolated. It is present in large quantities in all uncooked fruits and vegetables, and it is interesting to note that the popular idea that foods which have been kissed by the sun have a greater value than those which have not, finds some justification in the fact that vegetables grown above ground are much richer in the anti-scorbutic factor than root vegetables. This factor is well represented in fresh milk, but boiling, pasteurization, or evaporation completely destroys it.. The activity of the anti-scorbutic factor is much increased by germination; thus, beans, peas, or the grains of wheat or barley in the ordinary dry quiescent state contain no anti-scorbutic factor, but if they be placed in water and allowed to germinate, they immediately acquire this vitamine in large quantities. There is a practical application of this interesting fact which should not be lost sight of by travellers in inaccessible regions.
The Water-Soluble B. — Prof. Gowland Hopkins of Cambridge published in 1912 an article entitled “Feeding Experiments Illustrating the Importance of Accessory Factors in Normal Dietaries,” in which he called attention to the serious effects upon the health of animals which resulted from the absence from their food of certain hitherto unrecognized principles. In the following year Casimir Funk claimed to have isolated a “Factor X” which corresponded to the absent principles described by Hopkins to which he gave the name of Vitamine, in the mistaken belief that the factor in question contained an amino-acid. In spite of its faulty derivation the name caught on, and the word vitamine is now employed to include any of those essential substances which Hopkins unfortunately described under the term “accessory.” The experiments of these two observers showed that the absence of the factor now known as the Water-Soluble B. was the cause of the disease known as beriberi, which a Dutch physician, Dr. C. Eykman, had in 1897 associated with the custom of eating polished or decorticated rice by the natives, to the exclusion of all other foods. Beriberi is a disease of the nerves, and it was found that other similar affections of the nerves, pellagra for example, could be experimentally produced by withholding this vitamine, and cured by reinstating it in the dietary; hence the term “anti neuritic” by which it is sometimes known. This factor is essential to the normal growth, development and well-being of young animals. It is present in great abundance in all quick or natural foods, in grains and eggs. It is also present in the brain, liver, sweetbread and kidneys of animals, whereas from muscle or ordinary meat it is relatively absent. Yeast contains this vitamine in large quantities. In the vegetable kingdom, the leguminosæ afford it, uniformly distributed throughout their substance; whereas in cereals it is confined to the outside covering; hence the importance of unpolished rice and whole meal bread. It is soluble in water, especially in slightly acidulated water, and in alcohol, but not in fats. It resists a relatively high temperature; it is present for example after boiling for a short period, but is destroyed at 120° C.
This vitamine, as indeed the whole conception of vitamines in general, was first described in 1901 by Dr. Eugene Wildiers of Antwerp (1878-1908) under the name of Bios. In a paper which appeared in La Cellule (Louvain) on April 2 1901 entitled “Nouvelle substance indispensable au développement de la levure,” this young Belgian observer set forth a good deal of the knowledge which we now possess, but no notice was taken of his work, and his conclusions were arrived at independently by a different route about 12 years later.
The Fat-Soluble A. — In the year 1913 the third vitamine was described by McCollum and Davis. Its absence was shown to provoke a disease of the eyes, characterized by œdema of the lids, ulceration of the cornea, blindness and ultimately death. These lesions, even when in an advanced state, were cured by the exhibition of the vitamine. The absence in some degree of this factor is held responsible by some for the disease known as rickets. Its presence is certainly necessary to the growth and normal development of young animals. It is found (a) in certain animal fats, i.e. milk, butter and glandular tissue; (b) in the green leaves of edible plants. It is thus interesting to note that though present in essential organs or so-called “noble” tissues, it is absent from connective tissue and reserve tissue, such as lard or the subcutaneous animal fats. Olive oil and other vegetable oils do not contain this vitamine, whereas cod-liver oil contains it in large quantities. Fat-Soluble A. is soluble in oil, but not in water. It resists high temperature better than the other two.
Such was the state of our precise knowledge in 1921 concerning these elusive substances. If only from the confused and cacophonic nomenclature, it is evident that this knowledge was still in a very embryonic state. That there is, in this matter, a very wide field of interesting and fruitful research awaiting us is obvious from the fact that the discovery of the vitamines has entirely altered our conceptions of the causes and origins of disease. Until lately disease was regarded as a sin of commission by some unseen and subtle agency; the vitamines are teaching us to regard it in some degree at any rate as a sin of omission on the part of civilized or hypercivilized man. By our habit of riveting our attention upon microbes and their toxins we had sadly neglected the side of the question which concerns itself with our own defences. We sterilized our children's milk against the bacillus, and in so doing we deprived it of its vitamines and thus lowered the resisting power of the victim, not to one microbe only, but to all. The importance of vitamines has taught us that the naturally nourished child is practically immune from the majority of the diseases which in spite of our bacteriological and hygienic knowledge have been raising the infant death-rate to a figure which was as surprising as it was appalling. But it is to be remembered that in order to attain to this immunity a child must be born healthy; it must have been suitably nourished during its intra-uterine life, and this can only be attained by feeding the prospective mother upon foods which contain the necessary vitamines in such an abundance as will satisfy the physiological needs of two. The gross diseases due to absence of vitamines, such as scurvy, beriberi, pellagra and xerophthalmia, called the “deficiency diseases” (maladies de carence) are characterized by symptoms which are acute and unmistakable, but it is certain that long before these acute symptoms appear there will have been a general ill-defined departure from normal health, called by the French carence fruste or hypo-carence, and the condition may never pass beyond this stage. It is thus not only futile but actually dangerous to seek to estimate, as has often been done, the minimum amount of vitamine which will insure protection from obvious disease. What is required is not the minimum but the optimum. Amongst these conditions of hypo-carence may be mentioned the majority of the maladies due to the deficient action of the internal secretory or endocrine glands, such as the thyroid, thymus, supra-renals, pituitary, gonads and others, which have already been shown to suffer severely from deprivation of vitaminous foods. In the same category of hypo-carence are also to be placed many of the so-called metabolic diseases such as gout, arthritis, diabetes and others. These may be occasioned directly by the vitamine deficiency, or indirectly by starving one or more of the endocrine glands of the all-essential principles. As might easily be supposed, this relative lack of vitamines is peculiarly liable to show itself in the gastro-intestinal tract. Digestive difficulties and intestinal inertia, appendicitis and colitis have been shown in a great number of cases to have been due to a lack of vitamines in the ordinary foods, a fact of which anyone may convince himself in the matter of the widely distributed disease known as intestinal stasis or chronic constipation. It has often been remarked that dental caries or defective teeth is an evil which has seemed to be very much on the increase during the last 20 years; the period, that is, during which all fresh and unsterilized foods have been withheld from the young in order that they may be fed on devitalized pap which, in addition to requiring no mastication, is, by boiling and other culinary processes, completely deprived of the vitamine content so necessary to the proper development and eruption of the teeth themselves. Vitamines have already revolutionized our ideas on dietetics. The erstwhile stereotyped proportions of the proximate principles, proteins, carbohydrates, fats and salts which were considered essential to bodily health have been so altered by the discovery of the vitamines that the whole question will have to be investigated and studied afresh, and the ineffable theory of calories which was based on the curious assumption that the behaviour of food in the human body was identical with its behaviour in a test-tube, will retire to the limbo of things well forgotten. The discovery of the vitamines presents would-be scientists with a much-needed lesson in humility. It reminds us that, in evolving man, Nature provided him with the foods necessary to his growth, development and well-being, and that in interfering with these natural foods by cooking, sterilizing and refining, he has sacrificed their efficacy, sometimes to his greed, but more often to his arrogant assumption of superior knowledge, with the result that he has not only promoted the prevalence of preventable disease, but has actually created others which but for his misdirected energy would have had no existence.
Committee (British Government, 1919); Weill and Mouriquand, Alimentation et maladie par carence (1919); Dr. G. Houbert, La question des vitamines (1920); Raoul Lecoq, Les nouvelles theoriesalimentaires (1920).
- Journal of Physiology (1912), p. 425.
- Ueber die physiologische Bedeutung gewisser bisher unbekannten Nahrungbestandteile der Vitamine. Ergebn. Phys. (1913), 13, p. 125.
- “Vitamines et Stomatologie,” par H. Allacys, “Revue Beige de Stomatologie,” No. 9, Sept. 1920, p. 377.
- “The Necessity of Certain Lipins in the Diet during Growth,” Journ. Biol. Chem. (1913), p. 167.