Meta Information
ID:iron-gluconate
Name:
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-05-10T18:37:15.275350Z
Model
Gemini 3.1 Pro (High)
Interactions
Target id:
/intervention/bisphosphonates
Target name:
Bisphosphonates
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Iron binds to bisphosphonates, significantly reducing the absorption and effectiveness of both medications.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Instruct patients to take supplemental calcium and vitamin D if their dietary intake is inadequate; and to take calcium supplements, antacids, magnesium-based supplements or laxatives, and iron preparations at a different time of the day
Label source:
FDA label: Risedronate (Actonel)
Action type:
separate
Target id:
/intervention/levothyroxine
Target name:
Levothyroxine
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
4
Hours after target:
4
Description:
Iron binds to levothyroxine in the gut, which can significantly decrease its absorption and thyroid hormone effectiveness.
Actionable advice:
Doses should be separated by at least 4 hours.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
• Inform patients that agents such as iron and calcium supplements and antacids can decrease the absorption of levothyroxine.
Label source:
Action type:
separate
Target id:
/intervention/levodopa
Target name:
Levodopa
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Iron can bind with levodopa in the gut, reducing its absorption and effectiveness for Parkinson's symptoms.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Carbidopa and levodopa and iron salts or multivitamins containing iron salts should be coadministered with caution. Iron salts can form chelates with levodopa and carbidopa and consequently reduce the bioavailability of carbidopa and levodopa.
Label source:
Carbidopa-levodopa (Sinemet IR) FDA label, Precautions - Drug Interactions.
Action type:
separate
Target id:
/class/bile-acid-sequestrants
Target name:
Bile Acid Sequestrants
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
4
Hours after target:
4
Description:
These medications can bind to iron in the gut, preventing its absorption and reducing its effectiveness.
Actionable advice:
Doses should be separated by at least 4 hours.
Validation status:
validated_via_class_inference
Evidence tier:
tier_c
Evidence basis:
class_inference_summary
Evidence anchors:
Source url:
Established mechanism / class pharmacology (no single primary source quoted)
Exact phrase from label:
Mechanistic inference: bile-acid sequestrants bind iron in the gut and reduce ferrous gluconate absorption; separate dosing by several hours. Established class effect.
Label source:
Class inference
Action type:
separate
Target id:
/class/proton-pump-inhibitors
Target name:
Proton Pump Inhibitors
Severity:
major
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
These drugs reduce stomach acid, which is necessary for optimal absorption of iron from supplements.
Actionable advice:
It is important to talk to a doctor about timing.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Omeprazole can reduce the absorption of other drugs due to its effect on reducing Clinical Impact: intragastric acidity.
Label source:
FDA label: Omeprazole
Action type:
informational_none
Target id:
/intervention/famotidine
Target name:
Famotidine
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
This drug reduces stomach acid, which is necessary for optimal absorption of iron from supplements.
Actionable advice:
It is important to talk to a doctor about timing.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Drugs Dependent on Gastric pH for Absorption: Systemic exposure of the
concomitant drug may be significantly reduced leading to loss of efficacy.
Label source:
FDA label: Famotidine [class-derived from: Famotidine]
Action type:
informational_none
Target id:
/intervention/green-tea-extract
Target name:
Green Tea Extract
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Polyphenols (tannins) in green tea extract strongly bind to iron, inhibiting its absorption from the gut.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Polyphenolic compounds significantly inhibited heme-55Fe absorption in a dose-dependent manner.
Label source:
Ma et al. (Caco-2), PMID 22417433. Supports green-tea polyphenol/tannin iron inhibition.
Action type:
separate
Target id:
/intervention/calcium-citrate
Target name:
Calcium Citrate
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Calcium competes with iron for absorption in the gut, reducing the amount of iron the body receives.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The possibility of reducing calcium inhibition of iron absorption by decreasing calcium intake in lunch and dinner meals, which provided the most dietary iron, was examined in 21 healthy female volunteers.
Label source:
PubMed: Iron absorption from the whole diet: comparison of the effect of two different distributions of daily calcium intake. (PMID 7825544)
Action type:
separate
Target id:
/intervention/magnesium
Target name:
Magnesium
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Magnesium competes with iron for absorption in the gut, potentially reducing the amount of iron absorbed.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The addition of poorly water-soluble Mg compounds was shown to result in a drastic reduction in the amount of Fe contained in the supernatant. These data are in agreement with those reported in the literature.
Label source:
PubMed: Arzneimittel-Forschung (1994)
Source url:
Exact phrase from label:
Magnesium hydroxide, administered 1 hour post-iron ingestion at an oral dose of 4.5 g per g elemental iron ingested, significantly reduced iron absorption during a 12-hour period following simulated mild iron overdose in healthy adult human volunteers.
Label source:
PubMed: Academic emergency medicine : official journal of the Society for Academic Emergency Medicine (1998)
Source url:
Exact phrase from label:
It is concluded that MAH does not interfere with the enteral absorption of Fe-gluc when both electrolytes are orally administered together.
Label source:
PubMed: Arzneimittel-Forschung (1996)
Action type:
separate
Target id:
/dietary/polyphenol-rich-foods
Target name:
Polyphenol-rich Foods
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Polyphenols in foods like tea, coffee, and red wine bind to iron, inhibiting its absorption.
Actionable advice:
Doses and these foods should be separated.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Bioactive dietary polyphenols inhibit heme iron absorption in a dose-dependent manner. The small amounts of polyphenolic compounds present in foods are capable of reducing heme iron transport across the intestinal enterocyte.
Label source:
Ma et al. (Caco-2), PMID 22417433. Direct support for polyphenol inhibition of iron absorption.
Action type:
separate
Target id:
/intervention/vitamin-c
Target name:
Vitamin C
Severity:
moderate
Interaction type:
synergistic
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Vitamin C significantly enhances the absorption of non-heme iron by converting it to a more usable form.
Actionable advice:
It is best taken together with iron.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
OBJECTIVE: Our goal was to examine the effect of vitamin C on nonheme-iron absorption from a complete diet rather than from single meals.
Label source:
PubMed: Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet. (PMID 11124756)
Action type:
informational_none
Target id:
/intervention/zinc
Target name:
Zinc
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
High doses of zinc can compete with iron for absorption pathways in the gut, reducing effectiveness.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
In summary, the capacity to absorb iron did not influence 65Zn absorption, but both inorganic iron and heme-iron inhibited 65Zn absorption from zinc chloride.
Label source:
PubMed: Effects of iron, tin, and copper on zinc absorption in humans. (PMID 6475824)
Action type:
separate
Target id:
/intervention/copper
Target name:
Copper
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
High doses of copper can compete with iron for the same absorption pathway in the gut.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
In competition studies, we showed that Cu and Zn inhibited Fe uptake, and while Fe inhibited Cu uptake, Zn did not.
Label source:
PubMed: Biological research (2006)
Source url:
Exact phrase from label:
For example, excess enteral iron inhibits copper absorption in laboratory rodents and humans.
Label source:
PubMed: Biomedicines (2021)
Source url:
Exact phrase from label:
Iron supplements may inhibit intestinal zinc and copper uptake because these elements may compete for binding to a transporter molecule (divalent metal transporter 1) that is located on the apical side of the small intestinal epithelium.
Label source:
PubMed: The American journal of clinical nutrition (2003)
Action type:
separate
Target id:
/intervention/phytoestrogens-soy-isoflavones
Target name:
Phytoestrogens: Soy Isoflavones
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Compounds in soy products can bind to iron in the gut, significantly reducing its absorption.
Actionable advice:
Doses and soy intake should be separated.
Validation status:
validated_via_class_inference
Evidence tier:
tier_c
Evidence basis:
class_inference_summary
Evidence anchors:
Source url:
Established mechanism / class pharmacology (no single primary source quoted)
Exact phrase from label:
Mechanistic inference: soy reduces nonheme-iron absorption, but mainly via PHYTATE and soy protein - NOT via isoflavones/phytoestrogens. FLAG: reframe the mechanism to phytate/soy-protein; the ODS Iron sheet has no isoflavone-specific statement.
Label source:
Class inference
Action type:
separate
Target id:
/intervention/caffeine
Target name:
Caffeine
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Compounds like tannins found in caffeinated drinks (coffee, tea) can significantly reduce iron absorption.
Actionable advice:
Doses should be separated by at least 2 hours.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
However, iron content was 68.10% lower in green coffee beans with silver skin which might be due to its higher tannin content.
Label source:
PubMed: Unveiling the Compositional Analysis of Green Coffee Beans with and without Silver Skin. (PMID 38468525)
Action type:
separate
Target id:
/intervention/high-fiber-diet
Target name:
High-Fiber Diet
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Phytates in high-fiber foods like whole grains and legumes can bind to iron and reduce its absorption.
Actionable advice:
Iron is best taken between meals.
Validation status:
validated_via_clinical_guidance
Evidence tier:
tier_b
Evidence basis:
clinical_guidance_verbatim
Evidence anchors:
Exact phrase from label:
consuming other dietary components with nonheme iron, such as ascorbic acid and phytate, can significantly affect the bioavailability of nonheme iron.
Label source:
NIH ODS Iron fact sheet. REANCHORED (original PMID 2820047 not retrievable): phytate in whole grains/legumes reduces nonheme-iron bioavailability.
Action type:
informational_none