Growth and Reproduction of Rats on Vitamin C Free Diet.

Abstract

Harden and Zilva 1 and Drummond 2 believed that albino rats could not fully dispense with the antiscorbutic vitamin without restriction of their normal development. Osborne and Mendel 3 were unable to accept this conclusion since it had not been ruled out that the delayed development demonstrated by the first named authors was due to a vitamin B deficiency of their yeast preparation. Neither could it be ruled out that the growth-promoting effect of the fruit juices added was due to a more ample supply of vitamin B rather than to the vitamin C content of the juices.

Parsons 4 made the important observation that rats which had been fed on a practically vitamin C free diet for as long as 213 to 247 days showed considerable amounts of this vitamin in their livers. This, as McCollum 5 points out, constitutes conclusive evidence of synthesis of vitamin C by this species. Parson's experiment, however, does not directly answer the question whether better growth and nutrition could be secured by the addition of an antiscorbutic substance to the diet of albino rats.

The experiments here to be reported show that the addition of the antiscorbutic vitamin had no growth-promoting effect when given to white rats which for 2 generations or more had been reared and raised on a vitamin C free diet. The experiments were carried out on the third, fourth, and fifth generations. One group of the animals of the third generation, which did not receive any addition of vitamin C, was used as controls.

The experiment has extended almost 20 months. The basal diet was composed of: Soybean meal 35, mung bean meal 30, millet flour 30, NaCl 1, CaCO₃ 1.5 and cod liver oil 2. These ingredients, mixed with boiling water, were cooked in a double builer for 20 to 30 min. This diet invariably produced scurvy in guinea pigs and caused death in less than 4 weeks. As the source of vitamin C fresh cabbage (Peking variety) was used in amounts of 2 gm. per rat each day. The same amount fed to guinea pigs prevented scurvy indefinitely and supported normal growth.