50 MASS. EXPERIMENT STATION BULLETIN 436 



All things considered, home freezing in Massachusetts does not appear to be 

 as important as it may prove to be in certain other sections of the country. It 

 would appear that home freezing may be best used to supplement rather than to 

 replace other methods of home food preservation. 



Vitamin D Investigations, (L. R. Parkinson and C. R. Fellers.) Periodic 

 checks were made on the vitamin D content of Vitamin D milks sold in New 

 England. These assays showed that of the 192 samples examined, 181 contained 

 at least 400 U.S.P. units per quart, 8 samples contained from 320-400 units, and 

 only 3 samples were seriously deficient. Direct irradiation of milk is no longer 

 practiced in this State. The principal means of adding vitamin D to milk is by 

 direct addition of irradiated or activated ergosterol or purified fish oil concentrate. 



DEPARTMENT OF HOME ECONOMICS NUTRITION 

 Julia O. Holmes in Charge 



Utilization of Iron in Foods. 1. By Human Subjects. (B. V. McKey, A. W. 

 Wertz, D. C. Staples, and J. O. Holmes.) Four healthy women ranging in age 

 from 24 to 37 years participated as subjects of the experiment. During the four 

 and one half months of the study they received a basal diet which contained only 

 3.8 mg. of iron (about one-third of the amount recommended by the National 

 Research Council as a daily allowance for women), but was adequate in all other 

 respects. Beef muscle, approximately One fifth of a pound daily, was fed in 

 addition to the basal diet from the 65th to the 115th day of the experiment; and 

 iron sulfate, an iron salt frequently recommended by physicians as a source of 

 iron, was fed in a quantity equivalent to the iron in the beef, from the 116th to 

 the 130th day. During the experiment the four subjects donated approximately 

 1 pint of blood on the 1st, 15th, and 95th days, in an attempt to induce a mild 

 state of anemia which would insure maximal use of the iron in the foods. 



An anemia of clinical severity was not produced in any of the subjects. Fol- 

 lowing the second withdrawal of blood, the hemoglobin in only two of the sub- 

 jects fell as low as 90 percent of that usually found in normal, healthy young 

 women. Throughout the experiment the subjects were cheerful, energetic, and 

 felt well. The absorption of iron was as follows: 



Percentage Absorption of Iron 

 by the four subjects 



In the basal diet 3 14 23 



In the beef alone 19 44 51 36 



In the iron sulfate alone 26 37 19 



The woman who utilized the least iron in each of the diets was one who had 

 been severely anemic the preceding summer and had received iron medication 

 under a physician's prescription. It is probable that she made such poor use 

 of iron during the experiment because her body tissues were so saturated with 

 iron that the withdrawal of blood did not reduce her iron stores enough to allow 

 for absorption of new iron. The hemoglobin level of this subject after the second 

 blood donation within a IS-day period approximated that found in normal, 

 healthy non-donors of blood. 



These data indicate that all four of the women made more efficient use of the 

 iron in beef than in the iron salt. They also suggest that healthy women whose 

 body tissues are filled with iron can donate blood in the amounts and with the 

 frequency prescribed by the American Red Cross without serious depletion of 

 their iron stores, provided their diet is adequate in protein, vitamins, and min- 



