NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated August 1, 2026

Supplement × Prescription·Evidence index

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.

Read this first

An evidence index, not guidance.

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.

The research

7 studies naming Calcium and Omeprazole.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Omeprazole suppresses endothelial calcium response and eNOS Ser1177 phosphorylation in porcine aortic endothelial cells.

Molecular biology reports · 2021 · PMID 34291395

Animal study

“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.”

Kamiya et al. · Authors' conclusion

Names both Calcium and Omeprazole in its title.

Omeprazole Reduces Calcium Digestibility in Thoroughbred Horses.

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%.”

Pagan et al. · From the abstract

Names both Calcium and Omeprazole in its title.

Effect of L-lactic acid on calcium absorption in rats fed omeprazole.

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…”

Chonan et al. · From the abstract

Names both Calcium and Omeprazole in its title.

Medication and supplement pharmacokinetic changes following bariatric surgery: A systematic review and meta-analysis.

Obesity reviews : an official journal of the International Association for the Study of Obesity · 2024 · PMID 38710656

Systematic ReviewMeta-AnalysisHuman subjects1985 participants

“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.”

Lajeunesse-Trempe et al. · Authors' conclusion

Names Calcium and Omeprazole together in an interaction, co-administration, or pharmacokinetic context.

Do proton pump inhibitors decrease calcium absorption?

Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research · 2010 · PMID 20578215

Clinical TrialResearch Support, N.I.H., Extramural

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:

NutriStack

Track what you actually take.

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.