Component

All-trans-retinyl palmitate

Palmitate ester of all-trans-retinol; one retinyl ester species.

8 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. Maternal retinyl-palmitate supplementation rescued SYCP3-positive meiotic cells in vitamin A-depleted Lrat-null pups.

    All-trans-retinyl palmitate → Mouse germ-cell meiotic initiation source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    false
    experimental_model
    Dietary rescue experiment
    exposure
    100 U/day maternal retinyl palmitate from P5; assessment at P10.
    limitations
    Rescue of early markers is not proof of adult fertility or a human dose.
    nutrient_topic
    Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    plain_language
    Replacing the missing nutrient restored early meiotic development.
    primary_references
    [li2011] Vitamin A deficiency results in meiotic failure and accumulation of undifferentiated spermatogonia in prepubertal mouse testis. (2011). https://pubmed.ncbi.nlm.nih.gov/20881313/ DOI: 10.1095/biolreprod.110.086157
    tissue_or_cell_type
    neonatal testis
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 278–289

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

    ### va-repro-retinyl-palmitate-rescue Maternal retinyl-palmitate supplementation rescued SYCP3-positive meiotic cells in vitamin A-depleted Lrat-null pups. Condition category: nutrient_deficiency nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: Replacing the missing nutrient restored early meiotic development. organism: Mus musculus tissue_or_cell_type: neonatal testis experimental_model: Dietary rescue experiment limitations: Rescue of early markers is not proof of adult fertility or a human dose. exposure: 100 U/day maternal retinyl palmitate from P5; assessment at P10. cross_nutrient: false [li2011] Vitamin A deficiency results in meiotic failure and accumulation of undifferentiated spermatogonia in prepubertal mouse testis. (2011). https://pubmed.ncbi.nlm.nih.gov/20881313/ DOI: 10.1095/biolreprod.110.086157
    Complete structured claim and evidence

  2. CARET found increased lung-cancer incidence with beta-carotene plus retinyl palmitate versus placebo (relative risk 1.28).

    All-trans-retinyl palmitate → Lung cancer incidence source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    18,314 high-risk participants; mean four years.
    exposure
    30 mg/day beta-carotene plus 25,000 IU/day preformed vitamin A; trial stopped early.
    limitations
    Combined intervention cannot separate the contribution of each ingredient or establish their biochemical interaction.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    Combining the two forms did not produce the hoped-for protection.
    primary_references
    [va-omenn1996] Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease (1996). https://pubmed.ncbi.nlm.nih.gov/8602180/ DOI: 10.1056/nejm199605023341802
    tissue_or_cell_type
    Clinical lung-cancer incidence

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1731–1741

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 18,314 high-risk participants; mean four years. · source_derived_draft · unverified_draft

    ### va-caret-combination-lung-cancer CARET found increased lung-cancer incidence with beta-carotene plus retinyl palmitate versus placebo (relative risk 1.28). Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Combining the two forms did not produce the hoped-for protection. organism: Homo sapiens tissue_or_cell_type: Clinical lung-cancer incidence experimental_model: 18,314 high-risk participants; mean four years. limitations: Combined intervention cannot separate the contribution of each ingredient or establish their biochemical interaction. exposure: 30 mg/day beta-carotene plus 25,000 IU/day preformed vitamin A; trial stopped early. [va-omenn1996] Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease (1996). https://pubmed.ncbi.nlm.nih.gov/8602180/ DOI: 10.1056/nejm199605023341802
    Complete structured claim and evidence

  3. Vitamin A without iodine supplementation lowered TSH in the iodine-deficient study setting.

    All-trans-retinyl palmitate → Serum TSH concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    Vitamin A/iodine -> thyroid feedback.
    experimental_model
    404 children; factorial trial.
    limitations
    TSH-beta transcriptional suppression is an explanation, not a directly measured step in these children.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    Vitamin A status affected how strongly the thyroid was being stimulated.
    primary_references
    [va-zimmermann2007-iodine] Vitamin A supplementation in iodine-deficient African children decreases thyrotropin stimulation of the thyroid and reduces the goiter rate (2007). https://pubmed.ncbi.nlm.nih.gov/17921382/ DOI: 10.1093/ajcn/86.4.1040
    tissue_or_cell_type
    Pituitary-thyroid axis
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1578–1588

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 404 children; factorial trial. · source_derived_draft · unverified_draft

    ### va-iodine-context-lowers-tsh Vitamin A without iodine supplementation lowered TSH in the iodine-deficient study setting. Condition category: nutrient_deficiency nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Vitamin A status affected how strongly the thyroid was being stimulated. organism: Homo sapiens tissue_or_cell_type: Pituitary-thyroid axis experimental_model: 404 children; factorial trial. limitations: TSH-beta transcriptional suppression is an explanation, not a directly measured step in these children. cross_nutrient: Vitamin A/iodine -> thyroid feedback. [va-zimmermann2007-iodine] Vitamin A supplementation in iodine-deficient African children decreases thyrotropin stimulation of the thyroid and reduces the goiter rate (2007). https://pubmed.ncbi.nlm.nih.gov/17921382/ DOI: 10.1093/ajcn/86.4.1040
    Complete structured claim and evidence

  4. Thyroid volume and thyroglobulin decreased with vitamin A alone; total T4 showed no significant treatment-interaction effect.

    All-trans-retinyl palmitate → Thyroid volume source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Same trial.
    limitations
    Iodine treatment remained effective; nutrient roles are not interchangeable.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    Reduced thyroid enlargement did not establish a universal rise in thyroid hormone.
    primary_references
    [va-zimmermann2007-iodine] Vitamin A supplementation in iodine-deficient African children decreases thyrotropin stimulation of the thyroid and reduces the goiter rate (2007). https://pubmed.ncbi.nlm.nih.gov/17921382/ DOI: 10.1093/ajcn/86.4.1040
    tissue_or_cell_type
    Thyroid
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1590–1599

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

    ### va-iodine-context-thyroid-volume Thyroid volume and thyroglobulin decreased with vitamin A alone; total T4 showed no significant treatment-interaction effect. Condition category: nutrient_deficiency nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Reduced thyroid enlargement did not establish a universal rise in thyroid hormone. organism: Homo sapiens tissue_or_cell_type: Thyroid experimental_model: Same trial. limitations: Iodine treatment remained effective; nutrient roles are not interchangeable. [va-zimmermann2007-iodine] Vitamin A supplementation in iodine-deficient African children decreases thyrotropin stimulation of the thyroid and reduces the goiter rate (2007). https://pubmed.ncbi.nlm.nih.gov/17921382/ DOI: 10.1093/ajcn/86.4.1040
    Complete structured claim and evidence

  5. Five isotope studies did not confirm enhanced iron absorption after adding retinyl palmitate to corn-bread meals.

    All-trans-retinyl palmitate → Nonheme iron absorption source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Vitamin A/iron absorption replication disagreement.
    experimental_model
    Water/coffee meal conditions; stable and radioisotope methods.
    limitations
    Possible effect modification by poor vitamin A status remained unresolved; beta-carotene was not directly retested.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    Follow-up experiments did not reproduce the earlier positive result.
    primary_references
    [va-walczyk2003] No enhancing effect of vitamin A on iron absorption in humans (2003). https://pubmed.ncbi.nlm.nih.gov/12499334/ DOI: 10.1093/ajcn/77.1.144
    tissue_or_cell_type
    Intestinal absorption

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1566–1576

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Water/coffee meal conditions; stable and radioisotope methods. · source_derived_draft · unverified_draft

    ### va-iron-absorption-no-enhancement2003 Five isotope studies did not confirm enhanced iron absorption after adding retinyl palmitate to corn-bread meals. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Follow-up experiments did not reproduce the earlier positive result. organism: Homo sapiens tissue_or_cell_type: Intestinal absorption experimental_model: Water/coffee meal conditions; stable and radioisotope methods. limitations: Possible effect modification by poor vitamin A status remained unresolved; beta-carotene was not directly retested. cross_nutrient: Vitamin A/iron absorption replication disagreement. [va-walczyk2003] No enhancing effect of vitamin A on iron absorption in humans (2003). https://pubmed.ncbi.nlm.nih.gov/12499334/ DOI: 10.1093/ajcn/77.1.144
    Complete structured claim and evidence

  6. Vitamin A reduced the combined risk of death or major complications during severe-measles hospitalization in the trial.

    All-trans-retinyl palmitate → Major complications or death during measles hospitalization source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    189 hospitalized children; randomized trial.
    limitations
    No specific immune pathway was proven as mediator; not evidence for preventing all infections or replacing vaccination.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    A clinical benefit was demonstrated in a defined illness setting.
    primary_references
    [va-hussey1990] A randomized, controlled trial of vitamin A in children with severe measles (1990). https://pubmed.ncbi.nlm.nih.gov/2194128/ DOI: 10.1056/nejm199007193230304
    tissue_or_cell_type
    Clinical outcome

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1707–1716

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 189 hospitalized children; randomized trial. · source_derived_draft · unverified_draft

    ### va-measles-clinical-endpoint Vitamin A reduced the combined risk of death or major complications during severe-measles hospitalization in the trial. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: A clinical benefit was demonstrated in a defined illness setting. organism: Homo sapiens tissue_or_cell_type: Clinical outcome experimental_model: 189 hospitalized children; randomized trial. limitations: No specific immune pathway was proven as mediator; not evidence for preventing all infections or replacing vaccination. [va-hussey1990] A randomized, controlled trial of vitamin A in children with severe measles (1990). https://pubmed.ncbi.nlm.nih.gov/2194128/ DOI: 10.1056/nejm199007193230304
    Complete structured claim and evidence

  7. Retinyl palmitate attenuated the serum-calcium rise after calcitriol in the small crossover.

    All-trans-retinyl palmitate → Serum calcium concentration source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Retinyl ester/calcitriol/calcium interaction.
    experimental_model
    Nine adults; acute blinded crossover.
    exposure
    15 mg retinyl palmitate and/or 2 micrograms calcitriol; historical experiment, not advice.
    limitations
    Serum response is not a direct isotope absorption measurement, long-term fracture outcome or universal vitamin A:D ratio.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Homo sapiens
    plain_language
    Vitamin A form and exposure changed a measured vitamin D/calcium response.
    primary_references
    [va-johansson2001] Vitamin A antagonizes calcium response to vitamin D in man (2001). https://pubmed.ncbi.nlm.nih.gov/11585356/ DOI: 10.1359/jbmr.2001.16.10.1899
    tissue_or_cell_type
    Serum

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 1601–1612

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine adults; acute blinded crossover. · source_derived_draft · unverified_draft

    ### va-retinyl-palmitate-calcitriol-calcium Retinyl palmitate attenuated the serum-calcium rise after calcitriol in the small crossover. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Vitamin A form and exposure changed a measured vitamin D/calcium response. organism: Homo sapiens tissue_or_cell_type: Serum experimental_model: Nine adults; acute blinded crossover. limitations: Serum response is not a direct isotope absorption measurement, long-term fracture outcome or universal vitamin A:D ratio. cross_nutrient: Retinyl ester/calcitriol/calcium interaction. exposure: 15 mg retinyl palmitate and/or 2 micrograms calcitriol; historical experiment, not advice. [va-johansson2001] Vitamin A antagonizes calcium response to vitamin D in man (2001). https://pubmed.ncbi.nlm.nih.gov/11585356/ DOI: 10.1359/jbmr.2001.16.10.1899
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Lrat-null mice still secreted chylomicron retinyl esters whose acyl composition reflected the gavage oil.

    Lecithin:retinol acyltransferase / LRAT → Chylomicron retinoid delivery source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_location
    Figure 3
    experimental_model
    Lrat-knockout mice; retinol gavage and one-month retinoid-deficient diet.
    exposure
    6 micrograms retinol in peanut oil; P-407 clearance blockade; sampling at three hours.
    limitations
    Clearance was pharmacologically blocked; remaining enzyme identity was not established here.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    outcome
    Lrat-null mice still secreted chylomicron retinyl esters whose acyl composition reflected the gavage oil.
    plain_language
    Alternative esterification partly handles absorbed retinol when LRAT is missing.
    primary_references
    [va-obyrne-2005] Retinoid Absorption and Storage Is Impaired in Mice Lacking Lecithin:Retinol Acyltransferase (LRAT) (2005). https://pmc.ncbi.nlm.nih.gov/articles/PMC1352312/ DOI: 10.1074/jbc.M507924200
    tissue_or_cell_type
    Intestine and isolated chylomicrons
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 346–358

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Lrat-knockout mice; retinol gavage and one-month retinoid-deficient diet. · source_derived_draft · unverified_draft

    ### va-lrat-chylomicron-retinoids Lrat-null mice still secreted chylomicron retinyl esters whose acyl composition reflected the gavage oil. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Alternative esterification partly handles absorbed retinol when LRAT is missing. organism: Mus musculus tissue_or_cell_type: Intestine and isolated chylomicrons experimental_model: Lrat-knockout mice; retinol gavage and one-month retinoid-deficient diet. limitations: Clearance was pharmacologically blocked; remaining enzyme identity was not established here. exposure: 6 micrograms retinol in peanut oil; P-407 clearance blockade; sampling at three hours. outcome: Lrat-null mice still secreted chylomicron retinyl esters whose acyl composition reflected the gavage oil. evidence_location: Figure 3 [va-obyrne-2005] Retinoid Absorption and Storage Is Impaired in Mice Lacking Lecithin:Retinol Acyltransferase (LRAT) (2005). https://pmc.ncbi.nlm.nih.gov/articles/PMC1352312/ DOI: 10.1074/jbc.M507924200
    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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