PPIs reduce calcium carbonate absorption
Calcium carbonate requires stomach acid to dissolve. Long-term PPI use is associated with reduced bone density and increased fracture risk, partly via impaired calcium absorption.
On PPIs, switch from calcium carbonate to calcium citrate — citrate does not require gastric acid for absorption.
Take calcium with meals regardless of PPI timing
PPIs reduce calcium carbonate absorption. On PPIs, switch from calcium carbonate to calcium citrate — citrate does not require gastric acid for absorption.
Take calcium with meals regardless of PPI timing
This interaction is rated “Caution” by Formulate. Calcium carbonate requires stomach acid to dissolve. Long-term PPI use is associated with reduced bone density and increased fracture risk, partly via impaired calcium absorption.
Studies from our registry that mention calcium or ppi. Each links to the primary source and the other Formulate pages citing it.
Mentions calcium · 2015
Calcium intake and risk of fracture: systematic review
Bolland et al. · BMJ
Systematic review finding little evidence that increasing calcium intake prevents fractures in community-dwelling adults.
Mentions calcium · 2010
Iron bioavailability and dietary reference values
Hurrell R, Egli I · American Journal of Clinical Nutrition
Reviews enhancers (vitamin C, meat) and inhibitors (phytate, polyphenols, calcium) of non-heme iron absorption, providing the mechanistic basis for pairing iron with vitamin C and separating it from tea/coffee.
Mentions calcium · 2000
Prediction of dietary iron absorption: an algorithm for calculating absorption and bioavailability
Hallberg and Hulthén · American Journal of Clinical Nutrition
Foundational model for non-heme iron absorption factoring vitamin C, phytates, tannins, and calcium interactions.
Other interactions to know
Calcium significantly reduces iron absorption
Calcium blocks thyroid medication absorption
Long-term PPI use reduces B12 absorption
PPIs can cause hypomagnesemia
High calcium can impair magnesium absorption
Calcium may reduce zinc absorption
PPIs reduce non-heme iron absorption
Vitamin D enhances calcium absorption
Check your full stack in the free interaction checker.
The free checker lets you add any combination of supplements and medications at once. The free web app goes further — every stack change surfaces interaction alerts automatically.
Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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