DEVELOPMENTS IN THE CHEMISTRY OF VITAMINS
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Striking and unexpected effects of vitamin C have been revealed recently by
clinical medical experiments. It seems that with the aid of this vitamin an effec-
tive cure could be obtained of many diseases such as nephritis, haemophilia, pyor-
rhoea, etc., against which medicine and surgery were previously helpless. These
curative effects in pathological conditions which were never suspected before to
have any connection with a lack of vitamin seem to be very suggestive indicating
humanity to be suffering probably from a lack of vitamin C on a much more ex-
tensive scale than has hitherto been supposed. It is, therefore, considered a great
triumph for chemical science that in the short space of a couple of years this mys-
terious accessory factor of foods had been identified, its structure determined, its
synthesis effected and finally mad e available for medicine and industry.
The recent observations of Prof. Szent-Gyorgyi and others seem to show
that in paprica, at any rate, vitamin C is accompanied by a substance of similar
importance and related activity, particularly effective in curing certain acute
pathological conditions characterised by a morbid fragility of the capillary walls
of the skin, which by careful fractionation and study, has been identified as a pure
flavon or flavonol-glucoside. These results lack confirmation yet, but if found to
be correct, the large group of vegetable dyes known as flavons and flavonols will also
have to be added to the list of substances playing an important role in animal life.
IV. VITAMIN D
Although the problem of the chemistry of vitamin D had been attacked only
some seven years ago, the special deficiency disease known as rickets for which
this vitamin was the specific cure, had been recognised much earlier, the condi-
tion being principally one of weakness and malformation of the bony structures
as might be seen by the deformity of the leg bones and better by means of X-rays,
which revealed a curious coarse structure and frayed appearance at the ends of
the bones indicative of unsatisfactory calcification. Rapid advances in the study
of rickets were made at the time of the Great War when, on account of various
circumstances and particularly of the blockade of Central Europe, these defi-
ciency diseases, particularly rickets among children, became very common in those
countries. The scientific study of rickets was first made possible by Mellanby in
England who experimented with puppies, and showed how this disease could be
produced in the puppies at will, certain dietary factors present in cod-liver oil
and to a lesser extent in butter being found to play the primary part in curing
this disease. The confusion which arose from the similarity of distribution of
this anti-rachitic factor for dogs and the growth-factor known as vitamin A was
cleared up by the experiments of the American workers, Sherman, McCollum and
others, who made the interesting discovery that when the cod-liver oil was heated
in air at 100 degrees, the growth-promoting factor ' A ' was destroyed, while the
anti-rachitic factor remained. Vitamins A, B and C having already been recog-
nised, the new vitamin was called Vitamin D.