THE VITAMIN PRIMER.

Otago Witness, Issue 4032, 23 June 1931, Page 57

THE VITAMIN PRIMER.

By Sybil L. Smith, Senior Chemist, office of Experiment Stations, United States Department of Agriculture. What American scientists for the most part now call vitamin B is the vitamin which Eijkman first discovered in rice polishings and which was later named beriberi or antineuritic vitamin. Little by little a great deal was learned about vitamin B —the effects of lack of it upon the body, and its occurrence in foods. The fact that symptoms of vitamin B deficiency appear very quickly shows that, unlike vitamin A, it cannot be stored in the body to any extent. Feeding experiments with rats have also shown that it is difficult for the nursing mother to transfer enough vitamin B to her milk. This means that during pregnancy and lactation she should have an extra allowance' of vitamin B through the selection of foods particularly rich in this vitamin, or through the use of one of the' vitamin B concentrates, such as yeast extract or the wheat-germ sugar, vitavose. It is said that many breast-fed babies, formerly irritable, with poor appetite and unsatisfactory growth, respond quickly to increased vitamin B in the mother’s diet. Pediatricians are recommending some vitamin B concentrate as a routine procedure in infant feeding just as orange juice is given to provide vitamin C and cod-liver oil vitamins A and D. Yeast is one of the richest sources of vitamin B, and it was in experiments with the yeast that it was finally demonstrated that vitamin B is not a single substance, but is a mixture of the antineuritic vitamin and at least one other substance of quite different properties—the vitamin often referred to now as the antipellagric vitamin. It is of interest that part of the credit for the unexpected answer to the longdisputed question as to the identity of the antineuritic vitamin and vitamin B goes to one laboratory in the United States Public Health Service, in which the effect of dietary deficiencies in ex-

perimental tuberculosis in the rat was being studied, and part to another laboratory' in the same service, where the late Doctor Goldberger was working on the cause and cure of pellagra. Brewers’ yeast had been found by Goldberger to be very effective in the treatment of human pellagra as well as of blacktongue in dogs, a disease very similar to pellagra. It was the discovers’ that the yeast was equally effective after it had been heated to a -temperature known to destroy the antineuritic properties of vitamin B that led to the studies with rats in which it was demonstrated that vitamin B is made up of the antineuritic vitamin, easily destroyed by heat, and a more stable vitamin capable of preventing and curing a disease in rats and dogs similar to if not identical with human pellagra.

Since 1926 scientists have been busy unscrambling these vitamins —the antineuritic and the antipellagric. And the unscrambling has led to the perplexing discovery that, there may be more than two vitamins in the old vitamin B. It was difficult to know what to name vitamin B. English scientists still use vitamin B in its original meaning and call the two vitamins now known to be present in it Bl and 82. In America a similar scheme was first proposed, except that F and G were suggested in place of Bl and 82. Neither of the two proposals met with universal approval, and finally the terms B and G were proposed—B to stand for the antineuritic vitamin and G for the antipellagric. But the English still continue to use Bl and 82, and are already talking about a 83, and in popular literature an dfood adver tisements in this country, vitamin B is still used in its original meaning, while some scientists use Bl and 82, others B and G, and still others F and G for the two'vitamins already identified in vitamin B. Until the matter is settled all that can be done is to keep all the letters in mind and use the ones that seem most satisfactory. At present it seems less confusing to keep the B family together and call the members Bl and 82, for sooner or later we will have to make the acquaintance of B 3 and possibly B 4 and 85.

Vitamin Bl (new B or F) may be called the water-soluble, heat-labile, appetite-promoting, antineuritic vitamin. When foods known to contain the original vitamin B are heated at quite high temperatures, and particularly in an alkaline solution, the antineuritic vitamin Bl or new B is practically destroyed, leaving its companion 82, or G, almost entirely unharmed. That is why heatlabile is sometimes used to describe vitamin Bl and heat-stable vitamin 82. Foods thus treated no longer stimulate the appetite. It has been noted in vitamin B tests that rats refused to eat certain cooked foods, although the same food when raw would be relished. Now we know that this w r as because these foods no longer contained the appetiteproducing vitamin, and that if a little of this vitamin from any source what ever had been furnished, the food would have been eaten with relish.

It is seldom in this country that diets are so lacking in this vitamin that beriberi results. The condition more likely to happen is a digestive disturbance accompanied by irritability and nervousness—fretfulness in babies.

Thus far nearly everything that we have said about the old vitamin B seems to apply to vitamin 81. It is quite probable that the benefit to babies of a concentrate of vitamin B is due chiefly to its high content of vitamin 81, but wheat germ also contains some vitamin 82, and as yet we cannot attribute all of its success in infant feeding to vita min 81-.

Among natural foods, it is generally considered that cereal grains and seeds are beter sources of vitamin Bl than of 82, while the opposite is true of leafy vegetables, fruits, and probably milk. Too little is known as yet to make up lists of relative values of different foods in these tw’o vitamins. It is safe to assume, however, that foods which have been reported to be good sources of the old vitamin B must contain favourable proportions of the two, but that after heat treatment they will be less rich in vitamin 81.

The statement that seeds are richer sources of Bl Gian leaves does not mean that New England baked beans that have been parboiled with soda and baked in

a slow oven are richer in vitamin Bl than raw lettuce. On the other hand, the fact that heat tends to destroy this vitamin should not influence us to become raw-food faddists. The destruction is seldom complete and is compensated by the fresh foods included as a matter of habit. The danger of a deficiency in this vitamin is likely to be greater in large institutions where foods are often cooked well in advance of serving and are kept hot in steam tables.

A recent newspaper notice called .vitamin B2 or G the poor man’s vitamin, and this is not a bad name for it, for it* is the vitamin most needed to supplement the v corn bread, pork, and molasses (sorghum) diet common in localities in the south, where pellagra is prevalent. Its formal name is water-soluble, heatstable, antipellagric (?) vitamin. The question' mark simply means that we don’t feel quite sure as yet that lack of this vitamin is the sole cause of pellagra. Rats on a diet deficient in vitamin B2 develop a skin trouble very similar to the skin affection accompanying pellagra and are cured by foods rich in this vitamin. ’Hie same foods will cure blacktongue in dogs. And finally, the same foods are very effective in the treatment of human pellagra, particularly in preventing the periodic recurrence of the disease.

Among the richest sources of vitamin B2 are fresh lean meat, milk, liver, and eggs, all efficient sources of protein. It was believed at one time that pellagra was a protein-deficiency- disease. Now it seems more probable that it is the chance occurrence of vitamin B2 in foods rich in protein that led to this theory. The fact that some foods which are not good sources of protein, such as green leafy vegetables, are fairly good preventives "of pellagra, and that some good proteins, if carefully purified, have no effect upon the disease seems convincing enough evidence that pellagra is a vitamin-defieiency disease. Under ordinary circumstances, however, it is the effect of slight rather than extreme deficiencies in vitamin B2 that should concern us, and here again we turn to the rat to learn the effects of varying degrees of deficiency in this vitamin. Rats do not lose their appetite when deprived of vitamin 82, and consequently it takes much longer for symptoms to appear than in the absence of vitamin 81, when starvation complicates the picture. After a time, however, soreness of the eyes and mouth and occasionally of the nose develops and the rats become very weak and lethargic. The fur becomes soft and dry - and pulls out or is rubbed off easily, and the skin is Covered in places with a scaly crust. The whole appearance is that of a poorly nourished old animal. This has led to the suggestion that premature old age in human beings may result from long, continued deficiency of vitamin 82. Whether this is true or not, it is probable that the body requires vitamin B2 just as much as any other vitamin, and that diets high in cereals and fats and low in animal protein are apt to be lacking in this vitamin and should be supplemented with meat, milk, eggs, and green vegetables.

Vitamin 0 has but two descriptive adjectives, w’ater-soluble, anti-scorbutic, although heat-labile might be added, for it is most easily destroyed by heat in the presence of oxygen dr air. With modern methods of commercial canning it is now possible to exclude air so completely that fruits or vegetables canned immediately after picking are likely to be richer in vitamin C than the same materials allowed to stand for several days in the air. It is common knowledge that babies need orange juice or tomato juice to keep them from getting scurvy on a pasteurised milk or proprietary food diet; that explorers who must rely on dried foods need some concentrated source of vitamin C, but it is not so well known that every man, woman, and child needs vitamin C right along to keep the body, particularly the teeth, in good condition.

Soreness and stiffness of the joints, w’ith a tendency to hemorrhage, soreness of the gums with loosening of the teeth, and fragility of the bones are common symptoms of acute scurvy in guinea pig, and in human; while irritability, lowered resistance to infection, and a condition suspiciously like rheumatism may result from a little but not enough vitamin C.

A Swedish investigator, Hojer, made a study of the condition of teeth of guinea pigs on graded doses of vitamin 0, and concluded that slight differences in Die amount of vitamin 0 in foods could be detected more quickly and surely in this way than by waiting for scurvy to develop. In America Dr Percy Howe, of the Forsyth dental clinic, has long been emphasising the importance of vitamin 0 for tooth preservation. Recently Dr Hanke, of the University of Chicago, in collaboration with the Chicago Dental Research Club, has made a study of the relation of dietary deficiency to caries and other dental disorders, and has come to the conclusion that pyorrhoea is caused, indirectly at least, by lack of vitamin C. The inflammation of the gums, long known to be one of the early scurvy symptoms, is thought to lower the resistance of these tissues to infection, and this in-turn leads, to pyorrhea. This theory has been confirmed by marked success in the treatment of pyorrhoea by the use of large amounts of foods rich 1. in vitamin C, such as a pint, of orange juice containing the juice of one lemon, together with half a head of lettuce, daily.

Justification of such enormous doses of vitamin C is found in recent studies showing that it takes about twice as much vitamin C to protect the teeth as to prevent typical scurvy.

There is every reason why there should be a generous provision for vitamin C in the diet at all times. Like the other water-soluble vitamins, and . unlike the fat-soluble vitamins, it cannot be stored in the body to any great extent. Moreover, it is more easily destroyed than any other by heat and oxidation. Fortunately it is widely distributed in fruits and vegetables, many of which are ordinarily eaten raw. Oranges are considered the most ideal source of vitamin C, because they are not only very rich in vitamin C, but are always eaten raw. Little by little we are acquiring the habit of eating vegetables as well as fruits raw. Tomatoes, green peppers, water cress and lettuce—common ingredients of vegetable salads—are unusually rich in vitamins A, B, and C. Year by’ year it is becoming less difficult to provide for vitamins in the diet. It is no longer popular to take vitamins out of cereals. Witness the wheat-germ bread and irradiated muffets and farina. Intermittent sterilisation of vegetables in canning has given way to the quicker, less destructive pressurecooker process. Improvement in transportation facilities in cold storage makes it possible to secure really fresh fruits and vegetables the year round. And now comes the latest and most marvellous of inventions for the transportation and storage of foods—the quick-freezing process. It remains to be seen how the less stable vitamins stand up under the process, but it seems probable that the rapidity of the process will catch them unawares and prevent their destruction, and that the only danger of deterioration may be in the defrosting process if carried out too slowly. The story of the vitamins is not finished. There are probably more vitamins yet to be discovered. There is certainly much more to learn about the ones that have been discovered. Until we know more about how little of them we can get along with, it is a good plan to be almost faddists. concerning them. There is probably no fad that is as harmless and few as beneficial as the fad for vitamins.—Ladies’ Home Journal.