of 504 patients with low concentrations of vitamin b12 in serum by microbiologic assay ( less than 120 pg/ml ) in whom clinical information was available to evaluate vitamin b12 status , 109 ( 22 % ) were found to have clinically important deficiency of vitamin b12 , and another 10 had pernicious anemia with deficient serum levels of both vitamin b12 and folate .
C0042845
vitamin b12
C0002892
pernicious anemia