Vitamin B12 is present in foods of animal origin, including dairy products and eggs. Thus, vegetarians are more susceptible to a dietary deficiency of this important nutrient.1 Likewise, vitamin B12 serum concentrations are reported to be significantly lower in elderly population groups compared to younger groups.2-6 It is estimated that 10% to 30% of individuals over the age of 50 have low stomach acid secretion7,8 which results in decreased bioavailability of vitamin B12 from food.
