As far as we know, vegans need to supplement with B12 to prevent deficiency due to a higher risk of such.

How long does it take for B12 deficiency to develop, if a vegan person does not take any B12? If there is no access to supplementation, how long is it possible to live without any health risks like nerve damage etc.?

  • P.S. I understand it is hard to give an estimate, depends on many factors, but like inaccurate average values would be also ok.
    – Maxgmer
    Sep 19 '19 at 9:15
  • Some recent blood tests were good for everything except low B12 but I have not had previous tests so I don't know when it developed. I am now taking a supplement but it disappoints me that I need to; I prefer natural sources.
    – badjohn
    Sep 19 '19 at 10:09
  • 2
    It says you need to inject B12 every 2~3 months basis. Sep 20 '19 at 15:15
  • Why is this question marked as "duplicate" without a link? Also, I think the Game Changers movie says that even non-vegans tend to be low on B12 and that if they are less deficient than vegans it's because the animals they eat have been fed B12 supplements. I thought that was interesting.
    – Ryan
    Dec 19 '19 at 18:56