Component

Human sterol 27-hydroxylase / CYP27A1

Mitochondrial P450 with in-vitro vitamin D hydroxylation activity and substrate-dependent regioselectivity.

3 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. Human CYP27A1 hydroxylated ergocalciferol at C24 in the reported D2 substrate analysis.

    Human sterol 27-hydroxylase / CYP27A1 → 24-Hydroxyvitamin D2 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary abstract, substrate product positions and kinetic comparison.
    experimental_model
    Recombinant human CYP27A1 product identification
    exposure
    D2 incubation; concentration/time not reported in retrieved abstract.
    limitations
    D2 C24/C27 hydroxylation must not be mislabeled as C25 activation or assumed to be the main route in vivo.
    nutrient
    Vitamin D2 and D3 · Vitamin D2 and D3
    nutrient_topic
    Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin D2 and D3
    organism
    Homo sapiens protein
    plain_language
    CYP27A1 modifies D2 at carbon 24.
    primary_references
    [shinkyo2004] Metabolism of vitamin D by human microsomal CYP2R1. (2004). https://pubmed.ncbi.nlm.nih.gov/15465040/ DOI: 10.1016/j.bbrc.2004.09.073
    tissue_or_cell_type
    mitochondrial enzyme preparation

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 332–345

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human CYP27A1 product identification · source_derived_draft · unverified_draft

    ### vd-act-cyp27a1-d2-c24 Human CYP27A1 hydroxylated ergocalciferol at C24 in the reported D2 substrate analysis. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: CYP27A1 modifies D2 at carbon 24. organism: Homo sapiens protein tissue_or_cell_type: mitochondrial enzyme preparation experimental_model: Recombinant human CYP27A1 product identification limitations: D2 C24/C27 hydroxylation must not be mislabeled as C25 activation or assumed to be the main route in vivo. exposure: D2 incubation; concentration/time not reported in retrieved abstract. cross_nutrient: false evidence_location: Primary abstract, substrate product positions and kinetic comparison. nutrient: Vitamin D2 and D3 [shinkyo2004] Metabolism of vitamin D by human microsomal CYP2R1. (2004). https://pubmed.ncbi.nlm.nih.gov/15465040/ DOI: 10.1016/j.bbrc.2004.09.073
    Complete structured claim and evidence

  2. Human CYP27A1 hydroxylated ergocalciferol at C27 in the reported D2 substrate analysis.

    Human sterol 27-hydroxylase / CYP27A1 → 27-Hydroxyvitamin D2 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary abstract, substrate product positions and kinetic comparison.
    experimental_model
    Recombinant human CYP27A1 product identification
    exposure
    D2 incubation; concentration/time not reported in retrieved abstract.
    limitations
    D2 C24/C27 hydroxylation must not be mislabeled as C25 activation or assumed to be the main route in vivo.
    nutrient
    Vitamin D2 and D3 · Vitamin D2 and D3
    nutrient_topic
    Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin D2 and D3
    organism
    Homo sapiens protein
    plain_language
    CYP27A1 modifies D2 at carbon 27.
    primary_references
    [shinkyo2004] Metabolism of vitamin D by human microsomal CYP2R1. (2004). https://pubmed.ncbi.nlm.nih.gov/15465040/ DOI: 10.1016/j.bbrc.2004.09.073
    tissue_or_cell_type
    mitochondrial enzyme preparation

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 347–360

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human CYP27A1 product identification · source_derived_draft · unverified_draft

    ### vd-act-cyp27a1-d2-c27 Human CYP27A1 hydroxylated ergocalciferol at C27 in the reported D2 substrate analysis. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: CYP27A1 modifies D2 at carbon 27. organism: Homo sapiens protein tissue_or_cell_type: mitochondrial enzyme preparation experimental_model: Recombinant human CYP27A1 product identification limitations: D2 C24/C27 hydroxylation must not be mislabeled as C25 activation or assumed to be the main route in vivo. exposure: D2 incubation; concentration/time not reported in retrieved abstract. cross_nutrient: false evidence_location: Primary abstract, substrate product positions and kinetic comparison. nutrient: Vitamin D2 and D3 [shinkyo2004] Metabolism of vitamin D by human microsomal CYP2R1. (2004). https://pubmed.ncbi.nlm.nih.gov/15465040/ DOI: 10.1016/j.bbrc.2004.09.073
    Complete structured claim and evidence

  3. Human CYP27A1 catalyzed D3 25-hydroxylation in the recombinant comparison, with lower catalytic efficiency than CYP2R1.

    Human sterol 27-hydroxylase / CYP27A1 → Calcifediol / 25-hydroxyvitamin D3 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary abstract, substrate product positions and kinetic comparison.
    experimental_model
    Recombinant human CYP27A1/CYP2R1 comparison
    exposure
    Kinetic substrate comparison; CYP2R1 kcat/Km was reported 26-fold higher in this assay.
    limitations
    Does not establish CYP27A1 as the dominant human liver D3 25-hydroxylase.
    nutrient
    Vitamin D2 and D3 · Vitamin D2 and D3
    nutrient_topic
    Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin D2 and D3
    organism
    Homo sapiens protein
    plain_language
    A second enzyme can 25-hydroxylate D3 in laboratory assays.
    primary_references
    [shinkyo2004] Metabolism of vitamin D by human microsomal CYP2R1. (2004). https://pubmed.ncbi.nlm.nih.gov/15465040/ DOI: 10.1016/j.bbrc.2004.09.073
    tissue_or_cell_type
    mitochondrial enzyme preparation

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 317–330

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human CYP27A1/CYP2R1 comparison · source_derived_draft · unverified_draft

    ### vd-act-cyp27a1-d3 Human CYP27A1 catalyzed D3 25-hydroxylation in the recombinant comparison, with lower catalytic efficiency than CYP2R1. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A second enzyme can 25-hydroxylate D3 in laboratory assays. organism: Homo sapiens protein tissue_or_cell_type: mitochondrial enzyme preparation experimental_model: Recombinant human CYP27A1/CYP2R1 comparison limitations: Does not establish CYP27A1 as the dominant human liver D3 25-hydroxylase. exposure: Kinetic substrate comparison; CYP2R1 kcat/Km was reported 26-fold higher in this assay. cross_nutrient: false evidence_location: Primary abstract, substrate product positions and kinetic comparison. nutrient: Vitamin D2 and D3 [shinkyo2004] Metabolism of vitamin D by human microsomal CYP2R1. (2004). https://pubmed.ncbi.nlm.nih.gov/15465040/ DOI: 10.1016/j.bbrc.2004.09.073
    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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