A Simple Method for Production of Vitamin D Milk of Known and Controllable Potency

Abstract

Since the introduction of irradiated ergosterol and irradiated foods for the prevention and treatment of rickets, several methods have been employed in order to impart anti-rachitic properties to milk. Among these may be mentioned: (1) the irradiation of milk in both the powdered and liquid forms; (2) irradiation of the cow; and, (3) feeding to the cow substances containing large amounts of vitamin D, as for example cod liver oil or irradiated yeast. The irradiation of the cow as a means of imparting vitamin D to the milk is obviously most impractical from the commercial point of view, as is also the feeding of large amounts of cod liver oil. The irradiation of the milk itself has the practical disadvantage of being expensive since it involves the installation, maintenance and operation of expensive apparatus in the farm or dairy where it is employed. The direct irradiation of the milk and the indirect method of feeding irradiated yeast to the cow both have the disadvantage that they are not absolutely reliable methods of holding the vitamin D content at fixed concentration, so that repeated testing of the milk at regular intervals becomes necessary in order to be sure that the vitamin D content of the milk has not fallen below the standard.

In view of these difficulties it occurred to us that the method for adding fats to milk, which has been employed successfully by Holt, Tidwell and their associates, in our laboratories, for the past 4 years, might also be more practical for fortifying milk with vitamin D. Our procedure consists simply of homogenizing, in water, a concentrated oily solution of viosterol of known potency, with the aid of an emulsifying agent. We have tried several emulsifying substances, which are quite feasible as such, but in order to produce an emulsion which will be stable for months or years under ordinary environmental conditions, we have found lecithin to meet this requirement. This stable emulsion appears white as milk, is miscible with it, and has no objectionable odor or taste.