Dec. 1, 1925 
Inactivation of Vitamin A by Rancid Fat 
1023 
rancid series, since the rate of food consumption of the two series- 
was more nearly equal in the case of the males than in the case of the- 
females. 
Table IV.— Food-consumption data for experiment 2 , covering first 60 days 
Ration 
Rat 
No. 
Sex 
Total 
ration 
Coeffi¬ 
cient of 
food 
consump¬ 
tion ° 
Total 
gain 
Sweet___ ____ 
13 
Male.. 
Grams 
406 
Gram 
0.0705 
Grams 
110t 
Do___ 
15 
.do _ 
342 
.0558 
138. 
Average for males_ _ _ _ 
374 
.0631 
124 
Sweet_ _ ..._ 
14 
Female _ 
280 
.0691 
58. 
Do___ 
16 
...do_ 
274 
.0573 
76- 
Average for females. __ _ __ 
277 
.0632 
67 
Average for males and females... ___ 
325 
.0632 
95- 
Rancid_ _____ 
17 
Male_ 
300 
.0631 
75- 
Do_ 
19 
...do_ 
232 
.0578 
59* 
Average for males. ....._ 
266 
.0604 
67 
Rancid_ __ _ ___ _ . 
18 
Female 
290 
.0665 
60> 
Do_ __ ... _ 
20 
do 
209 
.0508 
72' 
Average for females ____ 
249 
.0586 
66- 
Average for males and females_ 
258 
.0595 
66. 
° See footnote to Table II. 
Yet it is somewhat remarkable that, whereas an approximate 
equivalence in rate of growth should have obtained between the two 
groups of females, the males of the control series should have grown 
so much more rapidly than the corresponding males receiving the 
rancid lard. In view of the fact that the latter rats received fully 
as much vitamin A as the former, it is difficult to understand the 
reason for their subnormal growth. 
One might, of course, postulate that animal appetite is largely 
determined by nutritive requirements, and that the greater greed 
with which the rats of the rancid series consumed their vitamin-A 
supplements was conditioned by their greater need for vitamin A as. 
compared with the control rats. One might further explain this, 
increased requirement by supposing that the rancid fat, after its. 
ingestion, effected a partial destruction of the vitamin A of the 
supplemental ration or even of the tissues. It would then be con¬ 
ceivable that the vitamin A actually supplied in this experiment was. 
sufficient to cover the thus increased requirements of the female rats 
of the rancid series, but was somewhat insufficient to provide for 
the more rapid growth of which the male rats of the rancid series, 
should have been capable. 
But as such reasoning involves a number of rather improbable- 
assumptions, and is highly speculative at best, we may well limit 
ourselves to observing that in this experiment, where the vitamin A 
was fed separately, the rancid lard, generally speaking, seemed to* 
affect the growth and the general health of the rats receiving it less, 
detrimentally than was the case in experiment 1, where the rancid 
lard came into intimate and prolonged contact with the vitamin A. 
