Value of estimating methylamalonic acid excretion in anaemia.

A rapid technique suitable for routine pathology laboratories has been used to estimate methylmalonic acid excretion in a 24-hour urine collection following a 10g. valine load. Levels above 40 mg./24 hours were found only in patients with vitamin B(12) deficiency. Patients with pernicious anaemia treated more than 24 hours before urine collection and patients with other types of anaemia had methylmalonic acid levels below 25 mg./24 hours.This method of demonstrating vitamin B(12) deficiency can be applied rapidly in debilitated patients so that specific treatment can be instituted within 36 hours of admission.