Component

Retinol-binding protein 4 / RBP4

Independent protein identity; organism and experimental state are specified on individual claims.

7 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What it acts on

  1. Circulating retinol became undetectable after one week of vitamin A-deficient feeding in adult Rbp4-null mice.

    Retinol-binding protein 4 / RBP4 → Serum retinol concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_location
    Abstract
    experimental_model
    Rbp4-knockout mice on vitamin A-sufficient and deficient diets.
    exposure
    Adult Rbp4-null mice placed on vitamin A-deficient diet.
    limitations
    Assay undetectability is model-specific, not a universal cellular threshold.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    outcome
    Circulating retinol became undetectable after one week of vitamin A-deficient feeding in adult Rbp4-null mice.
    plain_language
    Dietary supply could no longer compensate for lost transport from stores.
    primary_references
    [va-quadro-1999] Impaired retinal function and vitamin A availability in mice lacking retinol-binding protein (1999). https://pmc.ncbi.nlm.nih.gov/articles/PMC1171537/ DOI: 10.1093/emboj/18.17.4633
    tissue_or_cell_type
    Serum
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 388–400

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rbp4-knockout mice on vitamin A-sufficient and deficient diets. · source_derived_draft · unverified_draft

    ### va-rbp4-dietary-withdrawal Circulating retinol became undetectable after one week of vitamin A-deficient feeding in adult Rbp4-null mice. Condition category: nutrient_deficiency nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Dietary supply could no longer compensate for lost transport from stores. organism: Mus musculus tissue_or_cell_type: Serum experimental_model: Rbp4-knockout mice on vitamin A-sufficient and deficient diets. limitations: Assay undetectability is model-specific, not a universal cellular threshold. exposure: Adult Rbp4-null mice placed on vitamin A-deficient diet. outcome: Circulating retinol became undetectable after one week of vitamin A-deficient feeding in adult Rbp4-null mice. evidence_location: Abstract [va-quadro-1999] Impaired retinal function and vitamin A availability in mice lacking retinol-binding protein (1999). https://pmc.ncbi.nlm.nih.gov/articles/PMC1171537/ DOI: 10.1093/emboj/18.17.4633
    Complete structured claim and evidence

  2. Rbp4-null mice acquired hepatic vitamin A stores but could not mobilize them normally.

    Retinol-binding protein 4 / RBP4 → Hepatic retinol mobilization source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_location
    Abstract
    experimental_model
    Rbp4-knockout mice on vitamin A-sufficient and deficient diets.
    exposure
    Rbp4 knockout under sufficient and deficient feeding.
    limitations
    Alternative delivery operates with adequate intake; RBP4 is not the sole tissue supply route.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    outcome
    Rbp4-null mice acquired hepatic vitamin A stores but could not mobilize them normally.
    plain_language
    Stored vitamin A can remain inaccessible when its transport protein is absent.
    primary_references
    [va-quadro-1999] Impaired retinal function and vitamin A availability in mice lacking retinol-binding protein (1999). https://pmc.ncbi.nlm.nih.gov/articles/PMC1171537/ DOI: 10.1093/emboj/18.17.4633
    tissue_or_cell_type
    Liver and circulation
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 374–386

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rbp4-knockout mice on vitamin A-sufficient and deficient diets. · source_derived_draft · unverified_draft

    ### va-rbp4-store-mobilization Rbp4-null mice acquired hepatic vitamin A stores but could not mobilize them normally. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Stored vitamin A can remain inaccessible when its transport protein is absent. organism: Mus musculus tissue_or_cell_type: Liver and circulation experimental_model: Rbp4-knockout mice on vitamin A-sufficient and deficient diets. limitations: Alternative delivery operates with adequate intake; RBP4 is not the sole tissue supply route. exposure: Rbp4 knockout under sufficient and deficient feeding. outcome: Rbp4-null mice acquired hepatic vitamin A stores but could not mobilize them normally. evidence_location: Abstract [va-quadro-1999] Impaired retinal function and vitamin A availability in mice lacking retinol-binding protein (1999). https://pmc.ncbi.nlm.nih.gov/articles/PMC1171537/ DOI: 10.1093/emboj/18.17.4633
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. In a three-month cluster-randomized pilot, 20 g/day maternal Moringa leaf powder did not change human-milk vitamin A concentration or maternal and infant serum vitamin A status, although milk alpha-carotene rose modestly.

    Moringa dry leaf powder → Human-milk retinol concentration source_derived_draftungraded
    Experimental context and source evidence
    dose
    Corn porridge with or without 20 g/day leaf powder
    duration
    Three months
    evidence_access
    Primary PubMed abstract and indexed metadata reviewed. Full-text method details not stated here remain unresolved.
    evidence_scope
    literature_reviewed; model-specific source-derived curation
    experimental_model
    Forty-four completing Kenyan breastfeeding mother-infant pairs
    limitations
    The small pilot had baseline alpha-carotene imbalance and was not powered to establish clinical infant benefit.
    nutrient_topic
    Moringa oleifera chapter; interacting nutrients, drugs, peptides and proteins retain their experimental settings. · Moringa oleifera
    organism
    Forty-four completing Kenyan breastfeeding mother-infant pairs
    plain_language
    In a three-month cluster-randomized pilot, 20 g/day maternal Moringa leaf powder did not change human-milk vitamin A concentration or maternal and infant serum vitamin A status, although milk alpha-carotene rose modestly.
    primary_references
    Impact of Maternal Moringa oleifera Leaf Supplementation on Milk and Serum Vitamin A and Carotenoid Concentrations in a Cohort of Breastfeeding Kenyan Women and Their Infants. (2024). https://pubmed.ncbi.nlm.nih.gov/39408390/ DOI: 10.3390/nu16193425
    route
    Maternal oral feeding
    tissue
    Milk retinol/carotenoids and serum retinol-binding protein

    Moringa oleifera: mechanism of action and interactions (2026-09-20) · lines 255–264

    Original AI-assisted source-specific curation with primary-study citations, model, exposure, route, duration, negative findings and limitations preserved. Not publisher full text. · supports · Forty-four completing Kenyan breastfeeding mother-infant pairs · source_derived_draft · unverified_draft

    ## moringa-maternal-milk-retinol-null In a three-month cluster-randomized pilot, 20 g/day maternal Moringa leaf powder did not change human-milk vitamin A concentration or maternal and infant serum vitamin A status, although milk alpha-carotene rose modestly. Model/species: Forty-four completing Kenyan breastfeeding mother-infant pairs Tissue/system: Milk retinol/carotenoids and serum retinol-binding protein Exposure: Corn porridge with or without 20 g/day leaf powder Route: Maternal oral feeding Duration: Three months Limits: The small pilot had baseline alpha-carotene imbalance and was not powered to establish clinical infant benefit. Primary reference: Impact of Maternal Moringa oleifera Leaf Supplementation on Milk and Serum Vitamin A and Carotenoid Concentrations in a Cohort of Breastfeeding Kenyan Women and Their Infants. (2024). https://pubmed.ncbi.nlm.nih.gov/39408390/ DOI: 10.3390/nu16193425 Access: Primary PubMed abstract and indexed metadata reviewed. Full-text method details not stated here remain unresolved.
    Complete structured claim and evidence

  2. Iron increased plasma retinol, RBP and transthyretin; the combined iron/zinc arm increased retinol without significant carrier-protein increases.

    Iron → Plasma retinol concentration source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Iron/zinc -> retinoid transport markers.
    experimental_model
    Same factorial trial.
    limitations
    Measured biomarkers do not prove the molecular mechanism.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    The two minerals did not produce identical carrier-protein responses.
    primary_references
    [va-munoz2000] Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers (2000). https://pubmed.ncbi.nlm.nih.gov/10702174/ DOI: 10.1093/ajcn/71.3.789
    tissue_or_cell_type
    Plasma

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1495–1505

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Same factorial trial. · source_derived_draft · unverified_draft

    ### va-iron-improves-retinol-marker Iron increased plasma retinol, RBP and transthyretin; the combined iron/zinc arm increased retinol without significant carrier-protein increases. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: The two minerals did not produce identical carrier-protein responses. organism: Homo sapiens tissue_or_cell_type: Plasma experimental_model: Same factorial trial. limitations: Measured biomarkers do not prove the molecular mechanism. cross_nutrient: Iron/zinc -> retinoid transport markers. [va-munoz2000] Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers (2000). https://pubmed.ncbi.nlm.nih.gov/10702174/ DOI: 10.1093/ajcn/71.3.789
    Complete structured claim and evidence

  3. Inflammation reduced hepatic RBP mRNA and circulating transport proteins in the same rat study.

    Lipopolysaccharide → RBP4 mRNA source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    biomarker_context Imported condition classification; unverified.
    experimental_model
    Hepatic RNA and RBP/TTR assays.
    limitations
    Reduced secretion is inferred from the combined measurements, not measured as a complete flux chain.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Rattus norvegicus
    plain_language
    Transport regulation helps explain why blood retinol can fall during illness.
    primary_references
    [va-rosales1996] Effects of acute inflammation on plasma retinol, retinol-binding protein, and its mRNA in the liver and kidneys of vitamin A-sufficient rats (1996). https://pubmed.ncbi.nlm.nih.gov/8725149/ DOI: 10.1016/s0022-2275(20)42007-3
    tissue_or_cell_type
    Liver and plasma
    trigger_kind
    biomarker_context Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1685–1694

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Hepatic RNA and RBP/TTR assays. · source_derived_draft · unverified_draft

    ### va-lps-reduces-rbp-transcript Inflammation reduced hepatic RBP mRNA and circulating transport proteins in the same rat study. Condition category: biomarker_context nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Transport regulation helps explain why blood retinol can fall during illness. organism: Rattus norvegicus tissue_or_cell_type: Liver and plasma experimental_model: Hepatic RNA and RBP/TTR assays. limitations: Reduced secretion is inferred from the combined measurements, not measured as a complete flux chain. [va-rosales1996] Effects of acute inflammation on plasma retinol, retinol-binding protein, and its mRNA in the liver and kidneys of vitamin A-sufficient rats (1996). https://pubmed.ncbi.nlm.nih.gov/8725149/ DOI: 10.1016/s0022-2275(20)42007-3
    Complete structured claim and evidence

  4. Ttr-null mice had plasma retinol averaging about 6% of wild type.

    Transthyretin / TTR → Plasma retinol concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_location
    Abstract
    experimental_model
    Ttr-knockout mice; circulating and tissue retinoid assays.
    exposure
    Ttr knockout; pooled plasma comparison.
    limitations
    Not evidence that every tissue was depleted; the mechanism of the plasma fall was incompletely resolved.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    outcome
    Ttr-null mice had plasma retinol averaging about 6% of wild type.
    plain_language
    Loss of the RBP-associated carrier strongly lowers the blood measurement.
    primary_references
    [va-wei-1995] Studies on the metabolism of retinol and retinol-binding protein in transthyretin-deficient mice produced by homologous recombination (1995). https://pubmed.ncbi.nlm.nih.gov/7822324/ DOI: 10.1074/jbc.270.2.866
    tissue_or_cell_type
    Plasma
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 402–414

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Ttr-knockout mice; circulating and tissue retinoid assays. · source_derived_draft · unverified_draft

    ### va-ttr-plasma-retinol Ttr-null mice had plasma retinol averaging about 6% of wild type. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Loss of the RBP-associated carrier strongly lowers the blood measurement. organism: Mus musculus tissue_or_cell_type: Plasma experimental_model: Ttr-knockout mice; circulating and tissue retinoid assays. limitations: Not evidence that every tissue was depleted; the mechanism of the plasma fall was incompletely resolved. exposure: Ttr knockout; pooled plasma comparison. outcome: Ttr-null mice had plasma retinol averaging about 6% of wild type. evidence_location: Abstract [va-wei-1995] Studies on the metabolism of retinol and retinol-binding protein in transthyretin-deficient mice produced by homologous recombination (1995). https://pubmed.ncbi.nlm.nih.gov/7822324/ DOI: 10.1074/jbc.270.2.866
    Complete structured claim and evidence

  5. Zinc increased plasma retinol and transthyretin versus placebo; the RBP increase was not significant.

    Zinc → Plasma retinol concentration source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Zinc -> vitamin A biomarkers.
    experimental_model
    Six-month preschool trial.
    limitations
    No direct proof of restored liver release or increased RBP synthesis.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    Zinc status can influence vitamin A transport-related blood measurements.
    primary_references
    [va-munoz2000] Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers (2000). https://pubmed.ncbi.nlm.nih.gov/10702174/ DOI: 10.1093/ajcn/71.3.789
    tissue_or_cell_type
    Plasma

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1483–1493

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Six-month preschool trial. · source_derived_draft · unverified_draft

    ### va-zinc-improves-retinol-marker Zinc increased plasma retinol and transthyretin versus placebo; the RBP increase was not significant. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Zinc status can influence vitamin A transport-related blood measurements. organism: Homo sapiens tissue_or_cell_type: Plasma experimental_model: Six-month preschool trial. limitations: No direct proof of restored liver release or increased RBP synthesis. cross_nutrient: Zinc -> vitamin A biomarkers. [va-munoz2000] Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers (2000). https://pubmed.ncbi.nlm.nih.gov/10702174/ DOI: 10.1093/ajcn/71.3.789
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

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