It is vital to understand that there are no useful plant sources of B12. The foods listed below contain B12 analogues. This is false B12 and does not act as vitamin B12 in your body...
- Fermented soy
- Brewers yeast
These analogues (cobamides) can interfere with absorption of true vitamin B12 and disrupt B12 metabolism. Those who choose not to take vitamin B12 from fortified foods or supplements are at high risk of vitamin B12 deficiency, which can cause serious, long-term and irreversible health problems.
Warning - vegans and vegetarians who eat foods fortified with B12 and supplement orally could still be at risk of B12 deficiency for many reasons.
Even when you take in vitamin B12 from fortified foods or supplements, you may still be at risk of B12 deficiency if you have inherited genetic or autoimmune B12 absorption problems.
A deficiency could also arise from long-term use of drugs which deplete B12, such as proton pump inhibitors or metformin. In these cases a doctor diagnosing a deficiency, may prescribe low dose oral cyanocobalamin instead of injections which will be completely ineffective.
If the deficiency is caused by a proven dietary lack and the patient is heavily symptomatic, it would still be pertinent for the patient to receive some B12 injections in place of low dose oral cyanocobalamin tablets. This will help to bring B12 levels up far more quickly. Information on testing and treatment can also be found on this site.
For further information visit our What are the causes? page.
If you supplement correctly but suspect you may be B12 deficient please visit the What to do next page.
Please visit the Vegan Society for more information.
Information below supplied with kind permission of Sally M. Pacholok R.N. and Dr. Jeffrey J. Stuart.
Mothers with depleted B12 stores...
...who exclusively breast feed their babies unknowingly put them at great risk for developmental disability or even death. This is a common cause of B12 problems in infants; one study for instance, found that a group of six infants became ill after being nursed by vegetarian mothers. (The other half were born to mothers with undiagnosed pernicious anaemia).
Vegetarian and vegan mothers are devastated and feel tremendous guilt when their children suffer harm due to B12 deficiency, but in reality, most of these tragedies are the fault of doctors who fail to screen pregnant and nursing mothers for this deficiency - and who then often misdiagnose these women's children as mentally retarded or autistic, rather than considering B12 deficiency when the infants lose their speech, social skills and motor skills.