Vitamin B12 is a very important nutrient for people with vegan. How to prevent the symptom of B12 deficiency, babies and elderly at risk of B12 deficiency, how much B12 we need, sources of B12 and supplements.
Vitamin B12 deficiency is not uncommon. Vegans must be especially careful to get adequate amounts on a regular basis, preferably daily. A daily B12 supplement is necessary when B12-fortified plant foods are not regularly consumed. Nutrition labels on processed foods must be carefully studied to determine how much B12 is supplied by one serving of the food.
Resource: RD Resources for Consumers: Vitamin B12 in Vegetarian Diets.