Dec. 1, 1925 
Inactivation of Vitamin A by Rancid Fat 
1025 
in Table VI, however, it is obvious that the rats of the rancid series, 
consumed considerably less ration per day per gram of body weight 
than the corresponding controls; and we are left in doubt as to whether 
the deficiency was caused by a disappearance of vitamin A from the 
ration or by the limited food consumption. The average food con¬ 
sumption of the rats of the rancid series per day per gram of body 
weight, however, was 80 per cent of that of the control rats; and in 
view of the fact that the amount of egg yolk originally added to the 
ration was considerably in excess of that required for optimal growth 
of normal rats, we are inclined to believe that in spite of their limited 
food consumption the rats of the rancid series received enough egg 
yolk to have protected them from ophthalmia, if not to insure normal 
growth, had the vitamin A retained its potency. Therefore, while 
limited food consumption may have been, and probably was, a limit¬ 
ing factor in the growth of these rats, the evidence seems also to point 
to a loss of vitamin A from the ration containing the rancid lard. 
Table VI.— Food-consumption data for experiment 8, covering third to forty-eighth 
day , inclusive 
Ration 
Rat 
No. 
Sex 
Total 
ration 
Coefficient 
of food 
consump¬ 
tion « 
Total 
gain 
Sweet __ ... . . 
21 
24 
Male_ 
Grams 
371 
324 
Grams 
0.0874 
.0856 
Grams 
10L 
94- 
Do _ 
...do _ __ 
Average for males _ _ 
347 
.0865 
97 
Sweet____ 
22 
23 
Female_ 
..do 
378 
320 
.1038 
.0806 
9$ 
85 
Do___ 
Average for females.. _ __ 
349 
348 
.0922 
.0893 
80 
93- 
Average for males and females __ 
Raneid . _ ____ 
25 
28 
Male_ 
180 
204 
.0740 
.0676 
10 
21 
Do..__ 
...do_ 
Average for males _ __ 
192 
.0708 
15. 
Rancid_____ _ _ 
26 
27 
Female_ 
___do_ 
223 
172 
.0762 
.0681 
21 
21 
Do_ _ . _ 
Average for females __ - -- - -- 
197 
194 
.0721 
.0715 
21 
18. 
Average for males and females_ _ 
1 
1 
a See footnote to Table II. 
This idea is further supported by the periodic nature of the growth 
curves of the rats in the rancid series. These curves have been 
marked at points corresponding to the introduction of freshly mixed 
ration, and it will be observed that the periods of accelerated growth 
invariably follow closely upon the renewal of the ration. While the 
records of food consumption are not sufficiently detailed to show 
whether or not the accelerated growth was accompanied by increased 
food consumption, it is clear that the ration containing the rancid 
lard, unlike the ration containing the sweet lard, deteriorated with, 
increasing age; and the most plausible explanation of this fact would 
seem to be that the vitamin A of the ration was gradually destroyed 
by contact with the rancid fat. 
This experiment, therefore, seems to confirm the inference already 
drawn from experiment 1, viz, that rancid fat apparently destroys 
