Intestinal zinc absorption

What acts on it

1. Absorption efficiency increased as dietary zinc fell. After 4–8 weeks below 11 mg zinc/day, further adaptation reached as high as 92% absorption on low-phytate diets; this additional adaptation was absent on high-phytate diets.

   Zinc → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Phytic acid / phytate (dietary_modifier)

   evidence_location

   Indexed primary abstract.

   evidence_span

   {"source_cache": "artifacts/zinc-clinical-sources/hunt2008.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "da28b136fa7271f3406a8cf55cc3e613a5e8749578c1ee662057ebe564df8995", "utf8_bytes": 1647}

   experimental_model

   Three controlled dietary experiments in 109 healthy adults

   exposure

   Ten diets: 4–29 mg zinc/day, phytate:zinc molar ratios 2–7 or 15–23, before and after 4 or 8 weeks.

   limitations

   Dietary restriction and adaptation are not proof of clinical zinc deficiency. The reported 92% was an upper observed absorption value, not a mean.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Homo sapiens

   plain_language

   Zinc uptake can adapt to intake, but phytate constrained that adaptation.

   primary_references

   [zn-clin-hunt2008] Adaptation in human zinc absorption as influenced by dietary zinc and bioavailability. (2008). https://pubmed.ncbi.nlm.nih.gov/18469257/ DOI: 10.1093/ajcn/87.5.1336

   tissue_or_cell_type

   Intestinal absorption and candidate blood biomarkers

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 1317–1330

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Three controlled dietary experiments in 109 healthy adults · source_derived_draft · unverified_draft

   ### zn-clin-adaptation Absorption efficiency increased as dietary zinc fell. After 4–8 weeks below 11 mg zinc/day, further adaptation reached as high as 92% absorption on low-phytate diets; this additional adaptation was absent on high-phytate diets. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: Zinc uptake can adapt to intake, but phytate constrained that adaptation. organism: Homo sapiens tissue_or_cell_type: Intestinal absorption and candidate blood biomarkers experimental_model: Three controlled dietary experiments in 109 healthy adults limitations: Dietary restriction and adaptation are not proof of clinical zinc deficiency. The reported 92% was an upper observed absorption value, not a mean. exposure: Ten diets: 4–29 mg zinc/day, phytate:zinc molar ratios 2–7 or 15–23, before and after 4 or 8 weeks. cross_nutrient: Phytic acid / phytate (dietary_modifier) evidence_location: Indexed primary abstract. evidence_span: {"source_cache": "artifacts/zinc-clinical-sources/hunt2008.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "da28b136fa7271f3406a8cf55cc3e613a5e8749578c1ee662057ebe564df8995", "utf8_bytes": 1647} [zn-clin-hunt2008] Adaptation in human zinc absorption as influenced by dietary zinc and bioavailability. (2008). https://pubmed.ncbi.nlm.nih.gov/18469257/ DOI: 10.1093/ajcn/87.5.1336

   Complete structured claim and evidence

2. Adding histidine to the high-iron water solution attenuated inhibition, with zinc absorption of 47% compared with 34% at the high iron ratio without that ligand.

   L-Histidine → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Ferrous iron (competing_ion); Zinc(II) ion (absorbed_ion)

   evidence_location

   Indexed primary abstract.

   evidence_span

   {"source_cache": "artifacts/zinc-clinical-sources/sandstrom1985.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "aa462f6a961ec4190690f8def1be1f5e54491574698b131992161a989103ca76", "utf8_bytes": 1044}

   experimental_model

   Human 65Zn tracer study with whole-body counting after two weeks

   exposure

   Ferrous iron with ascorbic acid; Fe:Zn molar ratios 1:1, 2.5:1 and 25:1, in fasting water or a meal; histidine and iron-preloading comparisons.

   limitations

   Meal matrix, iron ratio and ligand differed. Absolute administered amounts and sample sizes were not verified in the indexed abstract; no universal spacing rule follows.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Homo sapiens

   plain_language

   A ligand changed the interaction between iron and zinc in this experiment.

   primary_references

   [zn-clin-sandstrom1985] Oral iron, dietary ligands and zinc absorption. (1985). https://pubmed.ncbi.nlm.nih.gov/3973750/ DOI: 10.1093/jn/115.3.411

   tissue_or_cell_type

   Intestinal absorption

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 1256–1269

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human 65Zn tracer study with whole-body counting after two weeks · source_derived_draft · unverified_draft

   ### zn-clin-histidine-iron Adding histidine to the high-iron water solution attenuated inhibition, with zinc absorption of 47% compared with 34% at the high iron ratio without that ligand. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: A ligand changed the interaction between iron and zinc in this experiment. organism: Homo sapiens tissue_or_cell_type: Intestinal absorption experimental_model: Human 65Zn tracer study with whole-body counting after two weeks limitations: Meal matrix, iron ratio and ligand differed. Absolute administered amounts and sample sizes were not verified in the indexed abstract; no universal spacing rule follows. exposure: Ferrous iron with ascorbic acid; Fe:Zn molar ratios 1:1, 2.5:1 and 25:1, in fasting water or a meal; histidine and iron-preloading comparisons. cross_nutrient: Ferrous iron (competing_ion); Zinc(II) ion (absorbed_ion) evidence_location: Indexed primary abstract. evidence_span: {"source_cache": "artifacts/zinc-clinical-sources/sandstrom1985.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "aa462f6a961ec4190690f8def1be1f5e54491574698b131992161a989103ca76", "utf8_bytes": 1044} [zn-clin-sandstrom1985] Oral iron, dietary ligands and zinc absorption. (1985). https://pubmed.ncbi.nlm.nih.gov/3973750/ DOI: 10.1093/jn/115.3.411

   Complete structured claim and evidence

3. Fasting-water zinc absorption was 59%, 58% and 34% at ferrous Fe:Zn molar ratios of 1:1, 2.5:1 and 25:1 respectively; inhibition was significant at the highest ratio.

   Ferrous iron → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Zinc(II) ion (absorbed_nutrient_ion); Iron (coadministered_nutrient); L-Ascorbate (coadministered_ligand)

   evidence_location

   Indexed primary abstract.

   evidence_span

   {"source_cache": "artifacts/zinc-clinical-sources/sandstrom1985.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "aa462f6a961ec4190690f8def1be1f5e54491574698b131992161a989103ca76", "utf8_bytes": 1044}

   experimental_model

   Human 65Zn tracer study with whole-body counting after two weeks

   exposure

   Ferrous iron with ascorbic acid; Fe:Zn molar ratios 1:1, 2.5:1 and 25:1, in fasting water or a meal; histidine and iron-preloading comparisons.

   limitations

   Meal matrix, iron ratio and ligand differed. Absolute administered amounts and sample sizes were not verified in the indexed abstract; no universal spacing rule follows.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Homo sapiens

   plain_language

   The high iron-to-zinc ratio reduced zinc uptake in the fasting solution.

   primary_references

   [zn-clin-sandstrom1985] Oral iron, dietary ligands and zinc absorption. (1985). https://pubmed.ncbi.nlm.nih.gov/3973750/ DOI: 10.1093/jn/115.3.411

   tissue_or_cell_type

   Intestinal absorption

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 1226–1239

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human 65Zn tracer study with whole-body counting after two weeks · source_derived_draft · unverified_draft

   ### zn-clin-iron-fasting Fasting-water zinc absorption was 59%, 58% and 34% at ferrous Fe:Zn molar ratios of 1:1, 2.5:1 and 25:1 respectively; inhibition was significant at the highest ratio. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: The high iron-to-zinc ratio reduced zinc uptake in the fasting solution. organism: Homo sapiens tissue_or_cell_type: Intestinal absorption experimental_model: Human 65Zn tracer study with whole-body counting after two weeks limitations: Meal matrix, iron ratio and ligand differed. Absolute administered amounts and sample sizes were not verified in the indexed abstract; no universal spacing rule follows. exposure: Ferrous iron with ascorbic acid; Fe:Zn molar ratios 1:1, 2.5:1 and 25:1, in fasting water or a meal; histidine and iron-preloading comparisons. cross_nutrient: Zinc(II) ion (absorbed_nutrient_ion); Iron (coadministered_nutrient); L-Ascorbate (coadministered_ligand) evidence_location: Indexed primary abstract. evidence_span: {"source_cache": "artifacts/zinc-clinical-sources/sandstrom1985.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "aa462f6a961ec4190690f8def1be1f5e54491574698b131992161a989103ca76", "utf8_bytes": 1044} [zn-clin-sandstrom1985] Oral iron, dietary ligands and zinc absorption. (1985). https://pubmed.ncbi.nlm.nih.gov/3973750/ DOI: 10.1093/jn/115.3.411

   Complete structured claim and evidence

4. When the corresponding iron-to-zinc ratios were administered with a meal, zinc absorption was 25%, 23% and 22%, without the inhibitory iron effect detected in fasting water. Two weeks of iron preloading also did not alter zinc absorption from water.

   Ferrous iron → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Zinc(II) ion (absorbed_nutrient_ion); Iron (dietary_context)

   evidence_location

   Indexed primary abstract.

   evidence_span

   {"source_cache": "artifacts/zinc-clinical-sources/sandstrom1985.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "aa462f6a961ec4190690f8def1be1f5e54491574698b131992161a989103ca76", "utf8_bytes": 1044}

   experimental_model

   Human 65Zn tracer study with whole-body counting after two weeks

   exposure

   Ferrous iron with ascorbic acid; Fe:Zn molar ratios 1:1, 2.5:1 and 25:1, in fasting water or a meal; histidine and iron-preloading comparisons.

   limitations

   Meal matrix, iron ratio and ligand differed. Absolute administered amounts and sample sizes were not verified in the indexed abstract; no universal spacing rule follows.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Homo sapiens

   plain_language

   The fasting-solution result did not carry over to the tested meal.

   primary_references

   [zn-clin-sandstrom1985] Oral iron, dietary ligands and zinc absorption. (1985). https://pubmed.ncbi.nlm.nih.gov/3973750/ DOI: 10.1093/jn/115.3.411

   tissue_or_cell_type

   Intestinal absorption

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 1241–1254

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human 65Zn tracer study with whole-body counting after two weeks · source_derived_draft · unverified_draft

   ### zn-clin-iron-meal When the corresponding iron-to-zinc ratios were administered with a meal, zinc absorption was 25%, 23% and 22%, without the inhibitory iron effect detected in fasting water. Two weeks of iron preloading also did not alter zinc absorption from water. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: The fasting-solution result did not carry over to the tested meal. organism: Homo sapiens tissue_or_cell_type: Intestinal absorption experimental_model: Human 65Zn tracer study with whole-body counting after two weeks limitations: Meal matrix, iron ratio and ligand differed. Absolute administered amounts and sample sizes were not verified in the indexed abstract; no universal spacing rule follows. exposure: Ferrous iron with ascorbic acid; Fe:Zn molar ratios 1:1, 2.5:1 and 25:1, in fasting water or a meal; histidine and iron-preloading comparisons. cross_nutrient: Zinc(II) ion (absorbed_nutrient_ion); Iron (dietary_context) evidence_location: Indexed primary abstract. evidence_span: {"source_cache": "artifacts/zinc-clinical-sources/sandstrom1985.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "aa462f6a961ec4190690f8def1be1f5e54491574698b131992161a989103ca76", "utf8_bytes": 1044} [zn-clin-sandstrom1985] Oral iron, dietary ligands and zinc absorption. (1985). https://pubmed.ncbi.nlm.nih.gov/3973750/ DOI: 10.1093/jn/115.3.411

   Complete structured claim and evidence

5. Zinc absorption fractions were 32.8±2.3%, 26.9±2.4%, 39.4±2.4% and 26.2±2.3% (mean±SE) for moderate-Ca/low-phytate, moderate-Ca/high-phytate, high-Ca/low-phytate and high-Ca/high-phytate menus. Phytate reduced absorption; calcium did not significantly impair it.

   Phytic acid / phytate → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   absolute_absorption

   Corresponding absolute absorption: 3.8±0.3, 3.0±0.3, 4.5±0.3 and 3.2±0.3 mg zinc/day (mean±SE).

   cross_nutrient

   Calcium (dietary_context); Zinc (measured_nutrient)

   evidence_location

   Indexed primary abstract.

   evidence_span

   {"source_cache": "artifacts/zinc-clinical-sources/hunt2009.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "d912d9f2c0890cde2ae13e9de7f1202bf130e661e3f14e13483563f179319f85", "utf8_bytes": 1659}

   experimental_model

   Two-by-two one-day feeding and 65Zn tracer study in ten healthy women

   exposure

   Approximately 700 versus 1800 mg calcium/day, and 440 versus 1800 mg phytate/day in conventional menus.

   limitations

   Short controlled menus in ten women; null calcium effect does not cover every formulation, population or dose.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Homo sapiens

   plain_language

   Phytate reduced zinc uptake in these menus, while extra calcium did not.

   primary_references

   [zn-clin-hunt2009] Dietary calcium does not exacerbate phytate inhibition of zinc absorption by women from conventional diets. (2009). https://pubmed.ncbi.nlm.nih.gov/19176739/ DOI: 10.3945/ajcn.2008.27175

   tissue_or_cell_type

   Intestinal absorption

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 1271–1285

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Two-by-two one-day feeding and 65Zn tracer study in ten healthy women · source_derived_draft · unverified_draft

   ### zn-clin-phytate-calcium Zinc absorption fractions were 32.8±2.3%, 26.9±2.4%, 39.4±2.4% and 26.2±2.3% (mean±SE) for moderate-Ca/low-phytate, moderate-Ca/high-phytate, high-Ca/low-phytate and high-Ca/high-phytate menus. Phytate reduced absorption; calcium did not significantly impair it. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: Phytate reduced zinc uptake in these menus, while extra calcium did not. organism: Homo sapiens tissue_or_cell_type: Intestinal absorption experimental_model: Two-by-two one-day feeding and 65Zn tracer study in ten healthy women limitations: Short controlled menus in ten women; null calcium effect does not cover every formulation, population or dose. exposure: Approximately 700 versus 1800 mg calcium/day, and 440 versus 1800 mg phytate/day in conventional menus. cross_nutrient: Calcium (dietary_context); Zinc (measured_nutrient) evidence_location: Indexed primary abstract. evidence_span: {"source_cache": "artifacts/zinc-clinical-sources/hunt2009.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "d912d9f2c0890cde2ae13e9de7f1202bf130e661e3f14e13483563f179319f85", "utf8_bytes": 1659} absolute_absorption: Corresponding absolute absorption: 3.8±0.3, 3.0±0.3, 4.5±0.3 and 3.2±0.3 mg zinc/day (mean±SE). [zn-clin-hunt2009] Dietary calcium does not exacerbate phytate inhibition of zinc absorption by women from conventional diets. (2009). https://pubmed.ncbi.nlm.nih.gov/19176739/ DOI: 10.3945/ajcn.2008.27175

   Complete structured claim and evidence

6. At added phytate-P levels of 0, 25, 50, 75, 100, 140, 175 and 250 mg, mean zinc absorption was 22%, 16%, 14%, 11%, 7%, 7%, 7% and 6%. Reductions were significant from 50 mg phytate-P in these meals.

   Phytic acid / phytate → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Zinc (absorbed_nutrient); Calcium (meal_context)

   evidence_location

   Indexed primary abstract.

   evidence_span

   {"source_cache": "artifacts/zinc-clinical-sources/hallberg2006.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "3a8556f5e4076009ed9adbf018205c8a3b2d0aaae43cccc866dc6be0271451d4", "utf8_bytes": 1603}

   experimental_model

   Human dual-radioisotope meal study: 40 subjects, 105 meals

   exposure

   Wheat-roll meals contained 3.1 mg zinc and 266 mg calcium; added sodium phytate supplied 0–250 mg phytate phosphorus.

   limitations

   Phytate-P mass is phosphorus mass, not total phytate mass. Seven-day calcium retention and zinc absorption are distinct endpoints; meal-specific significance levels are not universal thresholds.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Homo sapiens

   plain_language

   Increasing phytate progressively reduced zinc uptake in the test meal.

   primary_references

   [zn-clin-hallberg2006] Absorption of zinc and retention of calcium: dose-dependent inhibition by phytate. (2006). https://pubmed.ncbi.nlm.nih.gov/16632176/ DOI: 10.1016/j.jtemb.2006.01.003

   tissue_or_cell_type

   Intestinal zinc absorption and whole-body calcium retention

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 1287–1300

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human dual-radioisotope meal study: 40 subjects, 105 meals · source_derived_draft · unverified_draft

   ### zn-clin-phytate-gradient At added phytate-P levels of 0, 25, 50, 75, 100, 140, 175 and 250 mg, mean zinc absorption was 22%, 16%, 14%, 11%, 7%, 7%, 7% and 6%. Reductions were significant from 50 mg phytate-P in these meals. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: Increasing phytate progressively reduced zinc uptake in the test meal. organism: Homo sapiens tissue_or_cell_type: Intestinal zinc absorption and whole-body calcium retention experimental_model: Human dual-radioisotope meal study: 40 subjects, 105 meals limitations: Phytate-P mass is phosphorus mass, not total phytate mass. Seven-day calcium retention and zinc absorption are distinct endpoints; meal-specific significance levels are not universal thresholds. exposure: Wheat-roll meals contained 3.1 mg zinc and 266 mg calcium; added sodium phytate supplied 0–250 mg phytate phosphorus. cross_nutrient: Zinc (absorbed_nutrient); Calcium (meal_context) evidence_location: Indexed primary abstract. evidence_span: {"source_cache": "artifacts/zinc-clinical-sources/hallberg2006.abstract.txt", "locator": "Primary indexed abstract; complete local file", "file_sha256": "3a8556f5e4076009ed9adbf018205c8a3b2d0aaae43cccc866dc6be0271451d4", "utf8_bytes": 1603} [zn-clin-hallberg2006] Absorption of zinc and retention of calcium: dose-dependent inhibition by phytate. (2006). https://pubmed.ncbi.nlm.nih.gov/16632176/ DOI: 10.1016/j.jtemb.2006.01.003

   Complete structured claim and evidence

7. Raising rat dietary copper from 3 to 24 mg/kg reduced 65Zn absorption by about 20%; further increases to 300 mg/kg did not add inhibition or change zinc association with intestinal metallothionein.

   Copper → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Zinc (affected_nutrient); Rat intestinal metallothioneins measured without isoform resolution (unchanged_association)

   evidence_span

   {"source_cache": "artifacts/zinc-signaling-sources/479878-abstract.txt", "locator": "Primary indexed abstract", "file_sha256": "643b0358984f3caac8a20e3202c14a073d11ff88758c7a9637b6f8523195658b"}

   experimental_model

   Dietary radiotracer experiments in rats

   exposure

   High dietary zinc or copper and reciprocal 64Cu/65Zn absorption measurements.

   limitations

   High animal dietary concentrations are not human intake thresholds. Copper displacement from metallothionein was the authors’ mechanistic interpretation.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Rattus norvegicus

   plain_language

   Copper also affected zinc absorption, with a different response pattern.

   primary_references

   [zn-sig-479878] Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat. (1979). https://pubmed.ncbi.nlm.nih.gov/479878/ DOI: 10.1016/s0162-0134(00)80054-9

   tissue_or_cell_type

   Small intestine

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 929–941

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Dietary radiotracer experiments in rats · source_derived_draft · unverified_draft

   ### zn-sig-copper-zinc-absorption Raising rat dietary copper from 3 to 24 mg/kg reduced 65Zn absorption by about 20%; further increases to 300 mg/kg did not add inhibition or change zinc association with intestinal metallothionein. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: Copper also affected zinc absorption, with a different response pattern. organism: Rattus norvegicus tissue_or_cell_type: Small intestine experimental_model: Dietary radiotracer experiments in rats limitations: High animal dietary concentrations are not human intake thresholds. Copper displacement from metallothionein was the authors’ mechanistic interpretation. exposure: High dietary zinc or copper and reciprocal 64Cu/65Zn absorption measurements. cross_nutrient: Zinc (affected_nutrient); Rat intestinal metallothioneins measured without isoform resolution (unchanged_association) evidence_span: {"source_cache": "artifacts/zinc-signaling-sources/479878-abstract.txt", "locator": "Primary indexed abstract", "file_sha256": "643b0358984f3caac8a20e3202c14a073d11ff88758c7a9637b6f8523195658b"} [zn-sig-479878] Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat. (1979). https://pubmed.ncbi.nlm.nih.gov/479878/ DOI: 10.1016/s0162-0134(00)80054-9

   Complete structured claim and evidence

8. High luminal copper increased mucosal zinc accumulation while reducing zinc transfer to portal effluent at the highest luminal zinc concentration.

   Copper → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   cross_nutrient

   Zinc (affected_nutrient)

   evidence_span

   {"source_cache": "artifacts/zinc-signaling-sources/3968585-abstract.txt", "locator": "Primary indexed abstract", "file_sha256": "ca588cec5326d23dd5f8c9b409ea66fc415043b95af456399e495b8131c8f6ed"}

   experimental_model

   Isolated vascularly perfused intestine from diet-conditioned rats

   exposure

   Dietary copper/zinc variation for one week versus direct luminal-metal variation.

   limitations

   Ex-vivo perfusion and extreme luminal exposure differ from whole-animal feeding; increased metallothionein-bound copper alone did not prove reduced net absorption.

   nutrient_topic

   Zinc research collection; topical membership is not evidence of a direct dietary effect. · Zinc

   organism

   Rattus norvegicus

   plain_language

   Copper altered zinc movement through, as well as into, intestinal cells.

   primary_references

   [zn-sig-3968585] Copper and zinc absorption in the rat: mechanism of mutual antagonism. (1985). https://pubmed.ncbi.nlm.nih.gov/3968585/ DOI: 10.1093/jn/115.2.159

   tissue_or_cell_type

   Small-intestinal mucosa and portal effluent

   Zinc: transport, enzyme loading, deficiency and nutrient interactions (2026-09-17) · lines 971–983

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Isolated vascularly perfused intestine from diet-conditioned rats · source_derived_draft · unverified_draft

   ### zn-sig-luminal-copper-zinc High luminal copper increased mucosal zinc accumulation while reducing zinc transfer to portal effluent at the highest luminal zinc concentration. Condition category: normal nutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect. plain_language: Copper altered zinc movement through, as well as into, intestinal cells. organism: Rattus norvegicus tissue_or_cell_type: Small-intestinal mucosa and portal effluent experimental_model: Isolated vascularly perfused intestine from diet-conditioned rats limitations: Ex-vivo perfusion and extreme luminal exposure differ from whole-animal feeding; increased metallothionein-bound copper alone did not prove reduced net absorption. exposure: Dietary copper/zinc variation for one week versus direct luminal-metal variation. cross_nutrient: Zinc (affected_nutrient) evidence_span: {"source_cache": "artifacts/zinc-signaling-sources/3968585-abstract.txt", "locator": "Primary indexed abstract", "file_sha256": "ca588cec5326d23dd5f8c9b409ea66fc415043b95af456399e495b8131c8f6ed"} [zn-sig-3968585] Copper and zinc absorption in the rat: mechanism of mutual antagonism. (1985). https://pubmed.ncbi.nlm.nih.gov/3968585/ DOI: 10.1093/jn/115.2.159

   Complete structured claim and evidence

9. Apparent zinc absorption was unchanged in this study.

   Citrus pectin, preparation specified by study → Intestinal zinc absorption source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/pectin-research/6307932.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fd45607a7ff1d1a20dd52d145134da591847919c3db47ef8a8cf5693fb9f80a1", "start_char": 0, "end_char": 1593, "text_sha256": "fd45607a7ff1d1a20dd52d145134da591847919c3db47ef8a8cf5693fb9f80a1"}

   experimental_model

   Within-person ileostomy balance study; six participants

   exposure

   15 g/day citrus pectin on days 5-7 of a 10-day low-fiber feeding protocol

   limitations

   Ileal apparent absorption and output are not whole-body status or clinical deficiency; the colon was bypassed.

   nutrient_topic

   Pectin research collection; topical membership is not evidence of a direct dietary effect. · Pectin, structurally heterogeneous plant polysaccharides

   organism

   Homo sapiens

   plain_language

   An in-vitro zinc-binding result cannot simply be substituted for a human absorption result.

   primary_references

   [pectin-p6307932] The effect of citrus pectin on the absorption of nutrients in the small intestine. (1983). https://pubmed.ncbi.nlm.nih.gov/6307932/

   tissue_or_cell_type

   Small intestine; ileal effluent

   Pectin: metabolism, signaling and nutrient connections (2026-09-17) · lines 620–631

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Within-person ileostomy balance study; six participants · source_derived_draft · unverified_draft

   ### pectin-ileal-zinc-null Apparent zinc absorption was unchanged in this study. Condition category: normal nutrient_topic: Pectin research collection; topical membership is not evidence of a direct dietary effect. plain_language: An in-vitro zinc-binding result cannot simply be substituted for a human absorption result. organism: Homo sapiens tissue_or_cell_type: Small intestine; ileal effluent experimental_model: Within-person ileostomy balance study; six participants limitations: Ileal apparent absorption and output are not whole-body status or clinical deficiency; the colon was bypassed. exposure: 15 g/day citrus pectin on days 5-7 of a 10-day low-fiber feeding protocol evidence_span: {"source_cache": "artifacts/pectin-research/6307932.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fd45607a7ff1d1a20dd52d145134da591847919c3db47ef8a8cf5693fb9f80a1", "start_char": 0, "end_char": 1593, "text_sha256": "fd45607a7ff1d1a20dd52d145134da591847919c3db47ef8a8cf5693fb9f80a1"} [pectin-p6307932] The effect of citrus pectin on the absorption of nutrients in the small intestine. (1983). https://pubmed.ncbi.nlm.nih.gov/6307932/

   Complete structured claim and evidence