The vitamins : an epitome of contmporary knowledge / The Crookes Laboratories (British Colloids Ltd.).

  • Crookes' Laboratories.
Date:
[1938?]
Catalogue details

Licence: Public Domain Mark

Credit: The vitamins : an epitome of contmporary knowledge / The Crookes Laboratories (British Colloids Ltd.). Source: Wellcome Collection.

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    nape ay sap siae S : This compound closely resembling L clbshittinert Catan Ay an “chemical character was recently discovered in the liver oils of fresh- water fishes. It has not yet been fully identified, but it is probable that it has a biological activity similar to that of vitamin A,. Yet another vitamin A-lke substance is found in the liver oil of the whale. It 1s probably of similar constitution to vitamin A,, but containing a side chain of nine carbon atoms instead of eleven. It is distin- guishable from vitamin A, by the position of its absorption band in the ultra-violet region of the spectrum. Its biological activity is at present unknown. Physiological Effect Vitamin A is probably the physiologically active agent, but carotene and the vitamin produce the same effect when administered. The absorption of the vitamin from the intestine is usually more satisfactory than that of the parent pigment, hence a more prompt response follows treatment with materials containing the vitamin itself, e.g., high-potency liver oils. Some others of the natural lipochrome pigments, e.g., 5-carotene and kryptoxanthine, also give rise to vitamin A in the animal body. They are not, however, so important as f-carotene ; in the first place, because they are less common, and secondly, because they form only half the amount of A,. [ 6 ]
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