The Pathology of Thiamin, Riboflavin, Pantothenic Acid and Niacin Deficiencies in the Chick

Abstract

A nutritionally complete, isolated soybean protein diet was fed to chicks alone or modified with graded levels of thiamin, riboflavin or pantothenic acid. A casein basal diet was used to study niacin (and tryptophan) deficiencies. Deficient levels produced classical signs of each deficiency. In thiamin deficiency these included severe anorexia, retarded growth, nervous derangements and death. Riboflavin deficiency caused anorexia, retarded growth and, in moderate deficiencies, “curly toe” paralysis. Pantothenic acid deficiency caused retarded growth, nervous derangements and skin lesions. Niacin deficiency caused growth retardation and, at lower dietary levels, death. Histological studies disclosed no neurological lesions. Nervous signs appear to be due to biochemical lesions. Pantothenic acid-deficient chicks showed lymphoid cell necrosis in the bursa of Fabricius and the thymus, and a lymphocytic paucity in the spleen. All four deficiencies caused degeneration of the cells lining the duodenal crypts of Lieberkühn, with extreme dilation and filling of the crypts with cellular debris and necrotic cells, and vacuolation of the pancreatic acinar cells with hyaline body formation. These four vitamins act in coenzymes required for energy transfer metabolism. Their absence in the metabolically active cells of the duodenum and pancreas causes changes which are similar to those of cellular anoxia. Pair-fed controls showed no lesions in the duodenum, pancreas or other tissues except those attributable to low caloric intakes.