[Vitamin B12 levels in the serum in gastrectomized patients].

In 17 totally gastrectomised patients the vitamin B12-serum level was analyzed by 57Co-marked vitamin B12 according to the principle of competitive protein-bounding. Pathological low B12-serum levels in 10 patients refer to the lack of this vitamin. This, however, was only clinically manifested in one case by a megalocytic anaemia. The control of B12-serum levels by running substitution is only useful at the end of the interval between two injections. It is only at this time that it is a help in evaluating the effect of substitution. The monthly or 2-monthly vitamin B12-substitution should be preferred. No optimal substitutional effect can be achieved by injecting 1000 micrograms of vitamin B12 every three months.