gastric acid
2 interactions related to gastric acid
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.
omeprazole + iron
Omeprazole reduces absorption of nonheme (plant and supplemental) iron by raising stomach pH, which hinders the conversion of ferric (Fe3+) iron to the absorbable ferrous (Fe2+) form. Population data link long-term proton pump inhibitor (PPI) use with a higher risk of iron deficiency. A second, hormonal mechanism involving hepcidin and ferroportin has been proposed but rests on laboratory and animal work, not human outcomes.