Impaired utilization of serum folate in pernicious anemia: A study with radiolabeled 5-methyltetrahydrofolate

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Abstract

The possible role of cobalamins in the utilization of serum methyltetrahydrofolate has been investigated by means of radiolabeled methyltetrahydrofolate in subjects suffering from pernicious anemia. After intravenous administration, methyltetrahydrofolate-3H (SA 11,500 Ci/mole; dose 0.05 μg/kg) was cleared from the serum to tissues of B12-deficient subjects half as fast as after the same subjects had received vitamin B12 therapy. B12 deficiency was also associated with an increased rate of renal excretion of methyltetrahydrofolate or its derivatives, and a decreased rate of renal metabolism of methyltetrahydrofolate to other urinary folate derivatives.

Authors

Peter F. Nixon, Joseph R. Bertino