Value of Estimating Methylmalonic Acid Excretion in Anaemia

Abstract

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 B₁₂ 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 B₁₂ deficiency can be applied rapidly in debilitated patients so that specific treatment can be instituted within 36 hours of admission.