Effects of Vitamin B12 and Methionine on Excretion of Formiminoglutamic Acid by the Chick.

Abstract

Young chicks fed a diet deficient in vitamin B12 for 3-5 weeks excreted large amounts of formiminoglutamic acid (FGA) when compared to control chicks that received vitamin B12 in the diet. The high excretion rate of FGA by the vitamin 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 HC1, 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 vitamin B12, FGA excretion was quite high with either 4 or 24% of fat in the diet.