Abstract
A method for the estimation of vitamin B12 in erythrocytes using E. gracilis is described. In 29 normal subjects the mean value was 158 pg./ml. (S.D. 31 pg.) packed cells.
Five of 14 patients with untreated primary polycythemia had very low erythrocyte vitamin B12 levels, and in the group as a whole the value was significantly less than normal. In eight patients with secondary polycythemia the erythrocyte vitamin B12 did not differ from normal, though two patients had values below the normal range.
In 19 cases of pernicious anemia the mean erythrocyte vitamin B12 level was 53 pg./ml. (S.D. 32 pg.) packed cells which was significantly reduced. There was no constant relation between the erythrocyte and plasma levels. In eight cases of folate deficiency the erythrocyte vitamin B12 level was significantly reduced, with a mean value of 95 pg./ml. (S.D. 57 pg.) packed cells.