for phase ii the 24 surviving rats were randomized into three treatment groups -- one group remained vitamin a-deficient ( a- ) but received zinc and retinoic acid , the second remained zinc-deficient ( z- ) but received vitamin a and retinoic acid , and the third group was repleted with both zinc and vitamin a ( z+a+ ) and also received retinoic acid .
C0042839
vitamin a
C0040845
retinoic acid