Introduction: Vitamin B-12, also called Cobalamin Water soluble vitamin. It is the largest and structurally complex vitamin. Sources of Vitamin B12 are Produced by microorganisms (bacteria/fungi) inhabit in gut, Plants do not produce or contain VitaminB12. Liver, Kidney, Muscle, Egg, Milk, Cheese and other dairy products, Seafood and Foods fortified with B12 are also sources of the vitamin B12. Individuals who lack intrinsic factor have a decreased ability to absorb B12.Gastric acid releases the vitamin from food particles. Therefore antacid and acid-blocking medications may inhibit absorption ofB12.In addition some elderly people produce less stomach acid thereby increasing their probability of B12deficiencies. Methodology: In this observational study, 102 study patients were included on the basis of inclusion and exclusion criteria. The data was collected by administering a clinical questionnaire, relevant medical, drug history and dietary history. All baseline investigations, serum vitamin B12 level was investigated to document the deficiency. Data was analyzed through Epinfo using student`s t-test, Chi square test. p<0.05 was considered statistically significant. Result: It was observed that only (6.9%) of patients are deficient and (11.8%) are on borderline while as (81.4%) of study patients are not having any abnormality with regard to vitamin B12 deficiency. Among 102 patients ; 80 patients were prescribed PPI for peptic ulcer disease and rest 22 patients were having co morbid disease where PPIs were prescribed prophylactically. Around (6%) of patients are having deficiency in vitamin B12 who receive 40 mg dosage of PPI while as around (94%) of patients are not having any deficiency. However, around 12 percent of patients are having vitamin B12 deficiency who received 80 mg dosage of PPI and (88.2%) does not report any deficiency on this dosage. Discussion: The present study deficiency in Vitamin B12 alternatively named as cobalamin is a disorder that is most commonly seen in individuals who are beyond 59 years of age with a supporting prevalence of (10-40%). Vitamin B12 deficiency is generally thought to be synonymous with pernicious anemia (intrinsic factor deficiency); however, studies suggest that pernicious anemia is rare among types of vitamin B12 deficiency in the older population. Research conducted by Scarlet, suggested that most older adults with vitamin B12 deficiency have a normal Schillings test, but do not adequately absorb food-bound cobalamin.