NEW LIGHT ON VITAMINS

Dominion, Volume 22, Issue 70, 15 December 1928, Page 26

NEW LIGHT ON VITAMINS

PRESENT THEORIES CHALLENGED

Vitamins, which have for years been the playboys of tlie Eastern and the Western medical worlds, have now become suspect (writes the Medical Correspondent of the “Morning Post”). Without any names by which to identify them, they were known, somewhat as convicts, as Vitamins A, B. C, and D.

Its own special function was assigned to each one. Vitamin A was recognised to be present in fats and, more particularly in cod liver oil, fish roe and liver, and was regarded as essential for growth, fertility, and resistance to infection from diseases. Vitamin B, present notably in germinating seeds, came Into prominence chiefly in connection with beri-beri, when it was established that this disease was caused as a result of tlie removal of the vitamin by the polishing of rice.

Vitamin C is present in most juicy fruits and vegetables, and, as Captain Cook discovered, if these are absent from diet, scurvy results.. Vitamin D, which is one of tlie essential principles of cod liver oil. prevents rickets, and can be obtained artificially by treating such bodies as tlie important brain constituent cholesterol by solar or similar radiation. Somewhat of a bombshell —as far, at least, as the general public is concerned —lias been dropped into this new garden of science that was steadily ■icing weeded and tidied up. tlie chief boinb-tlirower being Dr. Melianby. of Sheffield, who a short time ago was awarded Hie gold medal of tlie British Medical Association. The vitamins apparently do not allogetlier work according to plan. Vitamin D. for instance, according to a paper written liy Dr. Melianby and Dr Green in the “British Medical Jourlit)],” is no longer to be regarded ns responsible for increasing I lie power of the lilood to kill germs. Tins fuiiction. if is stall’d, belongs to Vilaniin A. which is promoted to be Hie David that preserves us from Goliaths, such as pneumonia and bronchitis. Tlie trouble, ns Hie Medical Research ('ouueil pointed out some time ago. is that Vitamin A is by no means omnipresent. It is to be found, however, in the fatty substances of the liver of (lie salmon and lialibul. tlie grouse and I lie goose and oilier birds, and also in the liver lais of the sheep, the calf, and Hie ux -sheep and ox liver fat containing, for instance, ten times us much Vita-

min A as a good sample of butter. The disorder introduced /into the Vitamin world, however, hardly comes as a surprise to experts, and has already been anticipated. The whole research work done on the vitamins lias been a miracle of what can perhaps best be described as inductive chemistry. A vitamin‘has' never been isolated in Hie sense that it could be handled or seen, and its importance has been realised only by its fruits. If Vitamin D now has to give place to Vitamin A as Hie infection-resisting factor. His wll not perturb the experts, who. however, will still insist on the importance of ti well-balanced diet in which all vitamins, are. present. Commenting upon this, Dr.. Katherine Coward, who is in charge of tlie vitamin testing department of the Laboratory of Hie Pharmaceutical Society, stated that the work of Dr. Green and Dr. Melianby. just published, on the relations between the effects of Vitamin A and Vitamin D is unquestionably of great value and interest both to the professional worker on tlie subject and to Hie general public. ••So mucli emphasis.” she said, “lias been laid on Hie effects of Vitamin D probably because we know them so definitely. and perhaps for this reason Hie importance of Vitamin A lias been overlooked, very little experimental working having been done on animals with I lie latter, except in their relation to the promotion of growth. -The paper by Dr. Green and Dr. Melianby lias now definitely shown the "value of Vitamin A from the clinical standpoint, nmi proved it to lie air antiinfective agent, but it should be noted that they have not in any way questioned the value of Vitamin 1). “Tlie whole subject,” Dr. Coward continued, "is closely connected with Hull of sunlight, and as regards the beneficial effects claimed for sunlight if must not be forgotten that the value of I he ultra-violet rays in lite treatment of rickets is only one of probably in.anv effects of sunlight. ••The use of vitamins differs from Hie use of such agents as artitieial sunlight in Hie light from a mercury vapour lamp. “So far as one knows (here is no dam’cr of giving an excess of vitamins, whereas while Hie ultra-violet rays are certainly of anti-raebilie value it lias to be remembered that they are i>res,,„t in much larger proportions than those in sunlight. In both there are

many other rays also present, the effects of which, whether harmful or beneficial, have not yet been investigated.

"It cannot be too strongly urged that these lamps should only be used under medical direelion—a situation that is in strong emilrtist with that, of the vitamins which do not seem to be capable of producing a harmful etlecl. “All workers will be grateful.” Dr. Coward concluded, "to Dr. Green and Dr. Melianby for helping Io clear up Hie (lilliciilties inherent in tlie subject, for in so doing they will have contributed materially to the improvement of national health.”