Fermentation and Human Nutrition
Proceedings of the Nutrition Society
It is an over-simplification t o suggest that vitamin B" folic acid and the Lactobacillus caeei factor are one and the same. The following evidence supports the view that these factors are different: (1) Keresztesy, Rickes and Stokes (1943) have described the preparation from liver of a factor active for Strepto-COCCUB Zactis R but almost inactive for L. casei; (2) Chattaway, Dolby, Happold, McMillan and Waters have shown in unpublished work that a folic acid concentrate is inactive for L. emei
... nactive for L. emei unless certain unknown factors are added, while Chattaway, Dolby and Happold (1944) found that a liver preparation active for L. casei could be split into at least two components, one of which was obtained in a form having no stimulatory effect on S. lactis R; (3) Williams (1944) has recently referred to the "folic acids" and apparently believes that these are multiple factors. gave the following replies: To Miss Copping: Both pyridoxal and pyridoxamine, or a mixture of the two previously known as pseudo-pyridoxin, are as active as pyridoxin when tested on rats. Unfortunately they are far more potent than pyridoxin in stimulating the growth of certain micro-organisms, particularly Lactobacilli, and the results of microbiological tests of the vitamin B, content of foodstuffs may, therefore, be considerably higher than those of rat tests. To Dr. Baar: I agree with Dr. Baar that from published work pyridoxin appears to be the only factor the absence of which causes anaemia in pigs. On the other hand it is highly probable that the diet used in the experiments mentioned by Dr. Baar contained folic acid and, until further tests arc carried out with a diet known to be frcc from folic acid, no valid conclusions can be drawn as to the effect of folic acid deficiency on pigs.