One brand of nutritional yeast, Red Star T-6635+ (Vegetarian Support Formula) , is a reliable source of vitamin B12.
Most soy milks and soy products have vitamin B12 added.
Also there are B complex vitamin supplements available. The B vitamins need each other to work effectively.
Berocca contains 10 mcg of vitamin B12.
B-Fresh also makes gum and mints that contain vitamin B12.
For more information about vitamin B12 in the vegan diet, click on the link below -