Studies in vitamin A. 18. The effect of vitamin A deficiency on the pyruvate and α-ketoglutarate levels of rat blood

Abstract

A spectrophotometric method for the simultaneous detn. of blood pyruvate and alpha-keto-glutarate levels is descr. Using a carbohydrate-free diet essentially similar to that of von Euler and Hogberg (Naturwiss. 27: 769. 1940.), the claims of these authors that vit. A deficiency increases blood pyruvate levels in rats was not confirmed; alpha-ketoglutarate levels were also unaffected. Using a diet containing a normal proportion of carbohydrate and supplemented so as to meet the minimal vit. B1 requirements of growing rats, it was again impossible to demonstrate any effect of vit. A deficiency on blood pyruvate and alpha-ketoglutarate levels. On a carbohydrate-free diet a daily intake of 3.5 ug. of vit. B1 is insufficient to prevent raised blood pyruvate and alpha-ketoglutarate levels, irrespective of the vit. A status of the animals. On a normal diet, the minimal daily vit. B1 intake required to prevent increased blood pyruvate and alpha-ketoglutarate levels in rats is between 8 and 10 ug.