Effects of Vitamin B 12 and Methionine on Excretion of Formiminoglutamic Acid by the Chick. ∗

Abstract

Summary

Young chicks fed a diet deficient in Vit. B₁₂ for 3–5 weeks excreted large amounts of formiminoglutamic acid (FGA) when compared to control chicks that received Vit. B₁₂ in the diet. The high excretion rate of FGA by the Vit. B₁₂ deficient chicks was reduced to very low levels by incorporation of 1% DL-methionine into the diet for 24 hr. This effect was not observed with supplements of DL-homocysteine thiolactone HCl, DL-homocystine, L-cystine, choline chloride, or betaine. Although a high level of dietary fat had previously been found necessary to cause poor growth in the absence of Vit. B₁₂, FGA excretion was quite high with either 4 or 24% of fat in the diet.

The authors wish to thank Dr. Milton Silverman for many helpful discussions and for the forminoglutamic acid that was used as a standard, and Mrs. Esther M. Hurley, Mrs. Helen M. Hood, and Mr. Woodrow W. Duvall for excellent assistance with these experiments.