title: Analysis of fat-soluble vitamins. XVI. Antirachitic activity of 5,6-trans-vitamin D3 alone and in the presence of 5,6-cis-vitamin D3 resin, using chick bioassays.
abstract: Two biological assays were conducted in which the antirachitic activity in chicks of 5,6-trans-vitamin D3 added to feed is compared with that of 5,6-cis-vitamin D3. On the basis of the results obtained it is concluded that the relative potency of the trans isomer is, at the most, 5% and that the antirachitic activity of the trans isomer is not markedly enhanced (an increase to a relative potency of 16%, at the most) if the cis isomer is also included in the diet. The results are not conclusive on the inhibition or lack of inhibition of the antirachitic activity of 5,6-cis-vitamin D3 by the presence of 5,6-trans-vitamin D3 in the feed.
mesh_terms: D000821:Animal Feed; D000818:Animals; D001681:Biological Assay; D002645:Chickens; D002762:Cholecalciferol / Q000032:analysis / Q000494:pharmacology*; D005223:Fats; D007536:Isomerism; D008722:Methods; D012116:Resins, Plant; D012279:Rickets / Q000517:prevention & control*; D012995:Solubility
chemical_list: D005223:Fats; D012116:Resins, Plant; D002762:Cholecalciferol