cobalamin
4 interactions related to cobalamin
famotidine + vitamin b12
Famotidine, an H2-receptor antagonist, reduces gastric acid secretion and thereby impairs cleavage of vitamin B12 from food proteins, which is required for B12 absorption. The effect is less pronounced than with PPIs but is clinically relevant with long-term use.
esomeprazole + vitamin b12
Esomeprazole, the S-isomer of omeprazole, profoundly suppresses gastric acid required to liberate vitamin B12 from food proteins, impairing its absorption with long-term use. Studies confirm a dose- and duration-dependent reduction in serum B12 with chronic PPI therapy.
omeprazole + vitamin b12
Omeprazole suppresses gastric acid, which is required to cleave vitamin B12 from dietary proteins before it can bind intrinsic factor and be absorbed in the ileum. Long-term use (typically >2 years) is associated with measurably lower serum B12 levels and increased risk of clinical deficiency.
smoking + vitamin b12
Cyanide in cigarette smoke binds to active forms of vitamin B12 (methylcobalamin and hydroxocobalamin), converting them to the inactive cyanocobalamin form which is excreted, and chronic smoking damages the gastric mucosa, reducing intrinsic factor production and B12 absorption.