Ascorbic acid and vitamin B12
H. L. Newmark, J. M. Scheiner, M. Marcus and M. Prabhudesai
Using extraction procedures in which the extracted vitamin B12 was
protected by cyanide or metabisulfite, several investigators found no
change in vitamin B12 when meals were incubated in the presence of ascorbic
acid for 30 minutes at 37 degrees C. A previous report suggested
degradation of vitamin B12 under these conditions, but this was apparently
caused by incomplete protection of the extracted vitamin B12 in the assay
procedure. If incubation at 37 degrees C for 30 minutes is a laboratory
mimic of the gastric environment, one must conclude that high doses of
ascorbic acid do not affect the stability of vitamin B12 in vivo.
