Background: Background: Vitamin B12 (B12) deficiency leads to a wide spectrum of disorders affecting all age groups. However, reports on B12 status in vegetarian adults in India are limited. Hence, we determined the prevalence of B12 in the northern Indian vegetarian population. Methods: A cross sectional study was conducted in an urban north Indian population amongst 200 apparently adults distributed into 3 age groups: <20, 21-40 and >40 years. Plasma concentrations of B12 were analyzed. Results: The overall prevalence of B12 deficiency was 45%. B12 deficiency was higher in vegetarians (35.5%) compared to those consuming non vegetarian diet (9.5%). Conclusions: These results indicate a higher prevalence of B12 deficiency in apparently healthy vegetarian adults in a north Indian population