Liver B 12 in Subjects With and Without Vitamin B 12 Deficiency. A Quantitative and Qualitative Study

In six subjects with normal serum‐B 12 level the liver B 12 was about 1 μg per gram liver tissue wet weight. In the livers of eleven subjects with B 12 deficiency the B 12 content was only one fourth to one fiftieth of the normal amount. Methyl‐B 12 , deoxyadenosyl‐B 12 and hydroxo‐B 12 were demonstrated in control livers by the chromatographic‐bioautographic technique. Deoxyadenosyl‐B 12 was the major component. The liver methyl‐B 12 /deoxyadenosyl‐B 12 quotient was increased in four of seven subjects with vitamin B 12 ‐deficiency.