Abstract
As will be known from numerous papers, these two forms of vitamin D have different biological actions. In children and in chicks, one rat unit of the natural vitamin D of cod liver oil is about a hundred times as potent against rickets as one rat unit of irradiated ergosterol. Hence Steenboek1 has concluded that the two substances aro not identical. Chemical and physical proofs of the difference between the two substances have been advanced by Ender2, who showed that vitamin D2 differed from the natural vitamin D in its reaction with phthalic anhydride, its ultra-violet spectrum and its rotation of polarised light. As basic material, Ender used the liver fat of the tunny (Thunnus Thynnue) on the assumption that the vitamin D in various fishes is the same. However, Bills, Massongale and Imboden3 have found that one rat unit of Blue-fin tunny liver oil in chicks has only 15 per cent of the antirachitic effect of one rat unit of cod liver oil, whence they conclude that the two forms of vitamin D are different.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
