Calcium and Omeprazole: what the published research says
PubMed indexes 7 records that name Calcium and Omeprazole together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.
Every statement below is attributed to a named, dated, linked source.
This page lists published research relevant to Calcium and Omeprazole. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.
A study appearing here is not proof that an interaction exists. Two substances can be named together in a paper that never tested them in combination, and a source listed as background may cover only one of them.
Findings are quoted from each abstract as the authors wrote them. NutriStack has not re-analysed, pooled, or reconciled them, and they may disagree with each other.
NutriStack’s own interaction assessment for this pair is not published here. It has not completed qualified-human clinical review, so it is withheld from search. See the publication gate.
Nothing here is medical advice. Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen.
The research
7 studies naming Calcium and Omeprazole.
Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.
“Our results are the first to indicate that high doses of omeprazole may suppress both store-operated Ca2+ channels and partially the G protein-coupled receptor/phospholipase C/inositol 1,4,5-triphosphate pathway, and decreased BK-induced, Ca2+-dependent phosphorylation of eNOS(Ser1177). Thus, high dosages of omeprazole impaired EDRF production by attenuating intracellular Ca2+ signaling.”
Journal of equine veterinary science · 2020 · PMID 32067660
Animal study
“Omeprazole reduced apparent calcium digestibility from 52.0% to 41.4% in limestone and from 55.1% to 46.5% in BMC, equalling a 20.3% and 15.6% decrease in calcium digestibility in the limestone and BMC, respectively. Mineral source had a significant effect on calcium digestibility with BMC at 50.8% and limestone at 46.7%.”
Journal of nutritional science and vitaminology · 1998 · PMID 9742467
Animal study
“In a third experiment, a dietary sour milk beverage containing lactic acid (0.5 g/100 g of diet) increased the intestinal calcium absorption, but did not affect the gastric pH in rats fed omeprazole (0.03 g/100 g of diet). Although the significance of gastric acid in terms of overall calcium absorption is not known, under the present experimental conditions, the inhibition of gastric acid secretion by dietary omeprazole decreased the apparent calcium absorption, and the⦔
“This study demonstrates heterogeneity in practice and could not reach conclusive findings for most PK parameters. Prospective studies are needed to inform best practice and enhance patient healthcare and safety following bariatric surgery.”
Names Calcium and Omeprazole together in an interaction, co-administration, or pharmacokinetic context.
Names Calcium and Omeprazole together in an interaction, co-administration, or pharmacokinetic context.
Limitations
What this evidence cannot tell you.
Search-based evidence indexes have real limits, and it is worth being explicit about them:
Selection. These records were found by searching PubMed titles and abstracts for both substance names alongside interaction and pharmacokinetic terms. Relevant work that phrases things differently, or is not indexed in PubMed, will be missing.
No effect size. The quoted conclusions are the authors’ words about their own study. We have not extracted effect direction or magnitude, and a single study’s conclusion is not a consensus.
Population mismatch. Findings in healthy volunteers, animals, or a specific patient group may not transfer to you, your dose, or your formulation.
Absence is not safety. Few published studies means the combination is under-studied, which is not the same as established as safe.
Nearby evidence
Other pairs with published research.
Pages covering Calcium or Omeprazole alongside a different substance.
NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Calcium, Omeprazole, and several hundred other substances.
The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.