The Synthesis of Certain B Vitamins by the Rabbit

Abstract

Pantothenic acid and riboflavin are not essential dietary constituents for the growing rabbit. Diets containing as low as 0.31 µg of pantothenic acid and 0.33 µg of riboflavin per gram induced normal growth in rabbits. No symptoms of a vitamin deficiency were shown by the animals after ingestion of these diets for 112 days. When balance studies were carried out with 2 groups of animals fed the low-riboflavin diet with a daily intake of 11.1 and 17.0 µg, the corresponding total excretions were 127.1 and 265.1 µg of riboflavin per day. Two groups of rabbits fed a pantothenic acid deficient diet ingested daily 8.5 and 17.2 µg of pantothenic acid, and excreted 49.9 and 145.0 µg, respectively. Data obtained on the ingestion and excretion of biotin and folic acid indicate that these vitamins are also synthesized in this species. When 1% of sulfasuxidine was added to the diet, no symptoms specific for a pantothenic acid or riboflavin deficiency appeared, but 5 out of 10 rabbits developed diarrhea and died. Balance studies showed that with the addition of the sulfasuxidine to the diet, only the excretion of folic acid was decreased to a significant extent.