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The manner in which the "B" vitamin acts is still obscure. Voegtlin some time ago tried to demonstrate that it was identical with secretin and stimulated pancreatic flow. Recent work at the Johns Hopkins University by Cowgill and by Aurep and Drummond in England has failed to confirm this. One of its most marked immediate effects is increase in appetite. Karr in Mendel's laboratory has shown that dogs which refused their basal diet would resume eating it if they were allowed to ingest separately a little dried yeast. Karr studied the metabolism of these dogs as regards nitrogen partition but the results give little data that is explicatory of the behavior of the vitamin. In 1915 the author was able to bring about marked immediate improvement and the ultimate recovery of a number of infants who were of the marasmic type by merely increasing the "B" vitamin content of their food.

In these cases the vitamin was carried by Lloyd's reagent and administered mixed with cereal, or the crude extract was combined with the milk. The pancreas of the sheep was the source used. In these cases the growth curve changed abruptly from a decline to a sharp rise and this increase in weight continued and was accompanied by all the other signs of improved nutrition including increase in appetite. The change in the growth curve from decline to rise was accomplished without increasing or changing the basal diet but as the appetite increased the food had naturally to be increased to keep pace. In these cases the effect of the vitamin was to enable the child to utilize its normal food and to increase its appetite for it. This action certainly suggests stimulation of digestive glands. It also showed that even though the diet may contain the vitamin as was the case in the milk fed to these children the addition of the vitamin in concentrated form often gives an upward push that the food mixture fails to accomplish.

Daniels and Byfield have recently confirmed the effect of increased "B" in infant growth. Cramer has suggested in a paper published recently in The American Journal of Physiology that the fatty tissue about the suprarenals may be a depository of vitamin and that in the absence of vitamin this tissue loses its supply and that this is the explanation of lessened activity of that gland in certain metabolic disturbances. This idea tends to support the idea that vitamins are gland stimulants or hormones and the word food hormone has been suggested to describe them on that account. A few years ago Calkins and Eddy tried to determine the effect of the vitamin on the single cell by use of the paramecium but the results of the experiments failed to show a vitamin requirement on the part of these animals.

McDougall has recently suggested that the vitamins produce their effect on yeast cells by increasing hydration. Unfortunately nearly all stimuli which produce growth are accompanied by hydration effects and it is difficult to feel that this is a specific vitamin effect although without denying the possibility. Dutcher has tried to show that vitamins have a relation to oxidation effects. He observed that the issues of polyneuritic birds showed a marked reduction in catalase and that this catalase was restorable by curing the birds with vitamin. The main difficulty lies in the conflexity of factors that function between cause and effect.

These views are at best speculations. The literature is singularly lacking in detailed metabolic analyses of excreta of animals during vitamin stimulation and we know nothing of the possibilities of overdosage, for in all the work done it has been generally assumed that the presence of an amount greater than that necessary to produce normal growth is not material.

The exact manner of the vitamin's action then remains to be determined and it is obvious that this solution will come much more rapidly if we can first identify the substance chemically.

VI. The Physiological Properties of the "C" Vitamin

The steps that led to the acceptance of scurvy as a vitamin deficiency disease have already been discussed and show how the vitamin acts in such a disease. Practically all the work done with this vitamin to date has been concerned either with dosage or with reaction to heat, drying, etc. The only paper that we have seen that suggests another function than antiscorbutic power for this vitamin is the one by McCollum and Parsons in which they suggest that even in animals where scurvy does not exist, the presence of this factor may be necessary to normal metabolism.

A glance at this table shows the richest sources (see also table on page 59.) To these must be added canned tomato juice which Hess has shown practically equal to orange juice in efficiency and uses with infants in the same quantity. This discovery is of great value in instances where the cost of orange juice is often prohibitive.

La Mer and Campbell have presented some evidence to show that the antiscorbutic vitamin has a direct effect upon the adrenal glands. In their scurvy cases they find definite evidence of the enlargement or hypertrophy of this organ. Whether it affects other organs or not it remains to be shown.

Tags: Vitamins