cobalamin
4 interactions related to cobalamin
famotidine + vitamin b12
Long-term daily famotidine lowers stomach acid, which can modestly reduce absorption of vitamin B12 bound to food. Supplemental and fortified-food B12 are unaffected because they do not require stomach acid for absorption.
esomeprazole + vitamin b12
Esomeprazole and other PPIs suppress stomach acid, which can reduce absorption of food-bound vitamin B12 over long-term use; crystalline B12 in supplements is unaffected.
omeprazole + vitamin b12
Omeprazole suppresses gastric acid, which is needed to release vitamin B12 from dietary proteins before it can bind intrinsic factor and be absorbed. With long-term use this can lower serum B12 and, over time, contribute to deficiency. Supplemental (crystalline) B12 is not affected because it does not depend on stomach acid.
smoking + vitamin b12
Cigarette smoke can lower usable vitamin B12 by converting active coenzyme forms to inactive cyanocobalamin and by impairing gastric absorption, creating a low-grade nutritional draw rather than a dangerous reaction.