lo determine the average monthly potency of the milk and butter, 

 both according to the month of production and the month of 

 consumption. 



SUMMARY OF THE RESULTS 



The survey has not yet been completed in all of the cooperating 

 States. It is expected that each State experiment station will pub- 

 lish a detailed account of its own work when it is concluded and 

 that a final over-all report will be issued by the Technical Com- 

 mittee. 



Some 3,500 representative samples of butter have already been 

 analyzed, however, and the information thus obtained and evalu- 

 ated by the Technical Committee seems sufficient to warrant a 

 general appraisal of the vitamin A potency of the creamery butter 

 produced and marketed in this country. The purpose of this publi- 

 cation is to present a brief discussion of the results now available 

 on a Nation-wide basis in order to answer, entirely for practical 

 purposes, the questions raised by the Food and Nutrition Board. 

 The information bears mainly on three questions: 



1. The vitamin A potency of the creamery butter produced in 

 the various States. 



2. The effect of commercial storage and handling on the vita- 

 min A potency of butter. 



3. The vitamin A potency of butter sold on retail markets in 

 the United States. 



Results are now available which indicate the vitamin A potency 

 of the butter produced in creameries in 14 States. These States 

 make nearly 64 percent of the creamery butter produced in the 

 United States, and their combined output undoubtedly may be 

 considered representative of practically all the creamery butter 

 produced in this country. 



In all but one State there was a distinct difference between the 

 vitamin A potency of butter produced under winter-feeding con- 

 ditions and that produced under summer-feeding conditions. 

 About 36 percent of all the creamery butter is "winter" butter, 

 and it has an average vitamin A potency of approximately 11,200 

 International Units per pound. About 64 percent of all creamery 

 butter is "summer" butter, and it has an average vitamin A po- 

 tency of approximately 18,000 International Units per pound. 



Careful consideration of all the results of this study indicates 

 that the average vitamin A potency of the total output of creamery 

 butter in the United States is approximately 15,000 International 

 Units per pound. Thus, when the people eat as much butter as 

 they did immediately before the war (approximately 18 pounds 

 per capita) butter furnishes about 740 International Units of 

 vitamin A per capita per day, or about 14.8 percent of the daily 



