to determine the effect of niacin deficiency on pancreas , rats were fed a standard rat chow ad libitum or an equal amount of a niacin-deficient or niacin-sufficient diet in the first experiment , or of a niacin-tryptophan-deficient or niacin-tryptophan-sufficient diet in the second experiment .
C0030783
of niacin deficiency
C0027996
niacin