NutriStack
Iron and Lansoprazole, a caution.
Lansoprazole reduces absorption of non-heme iron salts that require gastric acid for dissolution. The Kaiser study of 77,000 iron-deficiency cases found that two or more years of PPI use was associated with about 2.5-fold higher risk of iron deficiency. Patients with menstrual losses or GI blood loss are at highest risk.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Iron and Lansoprazole
- Pair type
- Caution
- Evidence (highest tier)
- Strong
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Strong evidence
Caution
What is happening. Lansoprazole reduces absorption of non-heme iron salts that require gastric acid for dissolution. The Kaiser study of 77,000 iron-deficiency cases found that two or more years of PPI use was associated with about 2.5-fold higher risk of iron deficiency. Patients with menstrual losses or GI blood loss are at highest risk.
Mechanism. Gastric acid converts ferric iron to the absorbable ferrous form and solubilizes oral iron salts for uptake by duodenal DMT1. Lansoprazole also up-regulates hepcidin through an aryl hydrocarbon receptor pathway, further reducing intestinal iron transfer.
Recommendation. Take iron supplements at least 4 hours apart from lansoprazole. Iron bisglycinate or a heme-iron product is less affected by low gastric acid. Recheck ferritin and CBC 3 months after starting iron therapy.
Minimum separation. 240
Sources (2)
- Lam JR, Schneider JL, Quesenberry CP, Corley DA. Proton Pump Inhibitor and Histamine-2 Receptor Antagonist Use and Iron Deficiency. Gastroenterology. 2017;152(4):821-9. PMID 27890768
- Hamano H, Niimura T, Horinouchi Y, et al. Proton pump inhibitors block iron absorption through direct regulation of hepcidin via the aryl hydrocarbon receptor-mediated pathway. Toxicol Lett. 2020;318:86-91. PMID 31669099
Stack Score
How this pair moves the number.
Effect on the composite score
If both Iron and Lansoprazole are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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