[Efficiency of various B vitamins in zein base diets].

Lots of growing rats consume ad libitum rations based on zein (diets A), or zein partially supplemented in lysine and tryptophan (= protein quality of maize) (diets B), or zein supplemented in amino acids to fill totally its deficiencies (diets C). The diets contain 15 mg of niacin, 1.5 mg of thiamine, 2.5 mg of riboflavin and 1.5 mg of pyridoxine per kg. The efficiency of these vitamins is estimated according to their hepatic amounts. Compared with the diet A, the liver of animals of diet B contains in average 37 p. 100 less vitamins and that of diet C 56 P. 100 less. The amount of niacin in liver directly depends on the tryptophan intake and not on that of the niacin. The amount of riboflavin and pyridoxine depends on the nitrogen in the liver: the retention of 1 mg of nitrogen in the liver provokes the retention of 1.1 mug of riboflavin and of 0.2 mug of pyridoxine. The amount of thiamine is less narrowly linked to the hepatic nitrogen metabolism. The constitution of vitamin storage in the liver comes from the protein quality of the diet and from the possibilities of nitrogen storage.