Dear collective brain,
I have had a GP write to me asking for some help as one of his vegan patients presented him with the following information from the Vegan Society. Was anyone else aware of this and how did you deal with it?
Testing B12 status
A blood B12 level measurement is a very unreliable test for vegans, particularly for vegans using any form of algae. Algae and some other plant foods contain B12-analogues (false B12) that can imitate true B12 in blood tests while actually interfering
with B12 metabolism. Blood counts are also unreliable as high folate intakes suppress the anaemia symptoms of B12 deficiency that can be detected by blood counts. Blood homocysteine testing is more reliable, with levels less than 10 micromol/litre being desirable.
The most specific test for B12 status is methylmalonic acid (MMA) testing. If this is in the normal range in blood (<370 nmol/L) or urine (less than 4 mcg /mg creatinine) then your body has enough B12. Many doctors still rely on blood B12 levels and blood
counts. These are not adequate, especially in vegans.
Thanks,
Sally
Dr Sally Brady
Senior Clinical Scientist
Blood Sciences
The Hillingdon Hospital
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