The Chemistry and Physiology of Vitamin A

Determination of Carotene

“…This method, though desirable, is tedious, time-consuming, expensive, and subject to considerable error and the variations inherent in all bioassays. Biological methods for the determination of vitamin A activity have been adequately described elsewhere (37,38,39,60,94) and will not be further discussed here.…”

Chemistry of glycerol dichlorohydrin as a reagent for the determination of vitamin A

“…Although the medicinal use of cod liver oil was general in Western Europe by 1840 (83), it is only since the recog nition of deficiency diseases that progress regarding the cause of avitaminosis has been made. Detailed accounts of early work dealing with this subject are presented in Sher man and Smithes Monograph (201) (117) found that growth ceased prematurely in rats fed on a synthetic diet in which the fat supplied was lard* I^on the addition of butterfat or an ether extract of egg yolk to the diet growth was re sumed and it was oonoluded that the effect might be due to the presence of complex organic lipins or substances asso ciated with the latter.…”

“…MoCollxim and Davis (118) in 1914 demonstrated that it could be extracted from saponified butterfat. Numerous investi gators have since shown the vitamin to be concentrated in the nonsaponifiable fraction and many attempts to isolate it are based on this principle (see (83) and 187 120-125® C. at 5 X lO'^rm (85) 63-640C. (8) Soluble in most fats and or ganic solvents none 325-328 (172) 620 0^…”

“…The dietary deficiency of vitamin A may result in night blindness, poor growth, atrophy of epithelial tissues and tis sues of the eye. Increased lability to general infection and other difficulties* The physiology of this vitamin is ade quately covered by several reviews (13,83,185,187).…”