Preliminary experiments with the fat-soluble vitamine (vitamin A)

Abstract

The term “fat soluble vitamine” or “vitamin A” is here employed to designate the substance or substances occurring in butter fat, egg fat, codliver oil and elsewhere by virtue of which growth is promoted when the diet is otherwise adequate, and the characteristic eye disease, noticed especially in rats by Osborne and Mendel, is prevented and may often be cured. If, as indicated by some recent observations, especially those of Hess, the relations of butter fat and codliver oil to rickets are so different as to suggest that their vitamines are different substances, it becomes conceivable that more than one substance having growth-promoting and “antixerophthalmic” properties may be embraced under the one term “fat-soluble vitamine” or “vitamin A” as now used.

I. Distribution of the Substance or Substances “Vitamin A” between the Fatty and Aqueous Phases in Milk.-Several years ago McCollum stated in a brief note that fat soluble A is about thirty times more soluble in fat than in water, in which case skimmed milk will contain about half as much of this vitamine as whole milk. On the other hand, Mellanby, studying experimental rickets in puppies, and Hess and Unger in their studies of the clinical r81e of the fat soluble vitamine, appear to have assumed that their experimental diets could contain considerable amounts of skimmed milk, either in fluid or solid form, and still be nearly devoid of the fat soluble vitamine. According to our experience, skimmed milk contains a very significant amount of fat soluble vitamine, probably about half as much as whole milk as McCollum's brief statement would imply.

Our experimental evidence of the presence of significant amounts of fat soluble vitamine or “vitamin A” in skimmed milk is two-fold.