“…The haemopoietic effect of smaller doses of oral vitamin B12 has been shown to be enhanced by giving it with normal gastric juice and other sources of intrinsic factor (see Ungley, 1950;Glass and Boyd, 1953;Latner et al, 1953). Haematological responses have also been reported in cases of pernicious anaemia treated with oral aureomycin (Lichtman et al, 1950), and oral and parenteral penicillin were found to be effective in the megaloblastic anaemias described by Foy et al (1952). If the intrinsic factor present in normal gastric juice acts by protecting vitamin B12 from utilization by intestinal bacteria, as was indirectly suggested by the work of Ternberg and Eakin (1949), these antibiotics may have increased absorption of the vitamin by alteration of the bacterial flora.…”