Vitamin A Requirement of the Guinea Pig

Abstract

This study was undertaken to establish the dietary level of vitamin A best adapted to the growth and maintenance of the young guinea pig. Growth records were kept and plasma and livers were analyzed for vitamin A. Histological examinations of tissues of the eye, trachea, kidney and liver were made. Optimal growth occurred when the level of vitamin A was between 1.67 and 9.9 mg/kg of diet. Significant storage of the vitamin in the liver began at a level between 6 and 7 mg/kg of diet, and the quantity stored increased rapidly with further increase in the level of vitamin A in the diet. No such pattern was found in the levels of vitamin A in the plasma. Levels of 1.67 and 3.3 mg of vitamin A/kg, although maintaining normal growth, did not prevent metaplasia of epithelial tissue in all animals.