Iron oral (salts: sulfate, bisglycinate, fumarate, gluconate, polymaltose; heme iron polypeptide, lactoferrin) × Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate)
ModerateOral iron preparations; antianaemic agents×Mineral supplements. Trace elements
Updated · Methodology
Mechanism
Iron and zinc share the DMT1 transporter at the enterocyte brush border. Taken together on an empty stomach at supplement doses, iron, usually present in far larger amounts, displaces zinc. With food in between, the competition dilutes because other ligands come into play.
Symptoms
On the zinc side: altered taste, slow wound healing, more minor respiratory infections. These are rarely attributed to capsule timing.
Management
Two hours apart resolves most of it. If iron treatment is long-term and zinc is also prescribed, place them at opposite ends of the day. With meals both are better tolerated, at the cost of slightly less iron absorption.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
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Sources
- NIH Office of Dietary Supplements: Iron – Health Professional Fact Sheet (2025)– NIH ODS, Iron, Interactions with Medications
- NIH Office of Dietary Supplements: Zinc – Health Professional Fact Sheet (2025)– NIH ODS, Zinc, Health Risks from Excessive Zinc