Urinary methylmalonic acid as an indicator of the vitamin B12 status of grazing sheep

Authors: Lorentz PP, Millar KR
Publication: New Zealand Veterinary Journal, Volume 27, Issue 5, pp 90-92, May 1979
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Clinical pathology, Diagnostic procedures, Cobalt/vitamin B12, Trace elements, Urinary system/urology, Vitamins
Article class: Scientific Article

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Abstract: Lambs grazing cobalt-deficient pastures and injected with hydroxocobalamine gained significantly more weight and excreted significantly less methylmalonic acid in the urine than untreated controls. Lambs with liver vitamin B₁₂ levels in the range 0.1-0.2 μg/g excreted less than 25 μg of methylmalonic acid per ml of urine, whereas lambs with liver vitamin B₁₂ concentrations of less than 0.1 μg/g excreted greater amounts. Lambs in both groups had serum vitamin B₁₂ concentrations less than 500 pg/ml. No consistent diurnal variation in urinary methylmalonicacid concentrations was found for four lambs studied. There was a decrease in the methylmalonic acid levels of urine after storage for more than 24 hours which could be prevented by acidification of the urine. A mean urinary methylmalonic acid concentration greater than 30 μg/ml for 10 animals randomly selected from a flock would indicate a cobalt deficiency in the flock as a whole.

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