Observations on the Etiologic Relationship of Achylia Gastrica to Pernicious Anemia : XIII. Hematopoietic Activity of Vitamin B_12a (Vitamin B_12b)

1. Vitamin B_12a, derived from vitamin B₁₂ by catalytic hydrogenation, is as potent a hematopoietic agent as vitamin B₁₂ when administered parenterally to patients with pernicious anemia in relapse.

2. The hematopoietic activity of vitamin B_12a, like that of vitamin B₁₂, and of vitamin B_12b, is potentiated by simultaneous oral administration with normal human gastric juice.

3. Observations on one patient suggest that vitamin B_12a, like vitamin B₁₂, will arrest the progress of subacute degeneration of the spinal cord in pernicious anemia.