If your diet doesn’t provide you adequate amounts of vitamin B 12 rich foods and / or don’t synthesize sufficient amounts of the intrinsic factor which helps the body absorb vitamin B12, then you are bound to develop a deficiency of the vitamin. Also, these factors increase your chances of developing vitamin B 12 deficiency – Being vegan You’re 65 years or more You’re pregnant You’ve had a GI surgery. You take medications for diabetes and acidity