Component

25-Hydroxyvitamin D2

25-hydroxylated D2 precursor of the D2 hormone; separate from calcifediol (25-hydroxyvitamin D3) and total serum 25(OH)D. Study-defined 25-Hydroxyvitamin D2. Read each linked record for species, exposure and endpoint.

6 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 CYP24A1 had similar initial hydroxylation catalytic efficiencies for 25-hydroxyvitamin D2 and calcifediol in the matched vesicle assay.

    25-Hydroxyvitamin D2 → Calcifediol / 25-hydroxyvitamin D3 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary abstract: identified C24R products and comparative initial-rate kinetics.
    experimental_model
    Matched recombinant human CYP24A1 initial-rate kinetics
    exposure
    Comparative kcat/Km at low substrate availability; exact substrate range not reported in abstract.
    limitations
    This is an enzyme comparison; it does not measure binding-protein clearance, repeated dosing, or whole-person serum responses.
    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
    The two 25-hydroxy precursors were initially oxidized with similar enzyme efficiency.
    primary_references
    [li2023] Inactivation of vitamin D2 metabolites by human CYP24A1. (2023). https://pubmed.ncbi.nlm.nih.gov/37495192/ DOI: 10.1016/j.jsbmb.2023.106368
    tissue_or_cell_type
    phospholipid-vesicle membrane

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 542–555

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Matched recombinant human CYP24A1 initial-rate kinetics · source_derived_draft · unverified_draft

    ### vd-act-cyp24a1-precursor-selectivity Human CYP24A1 had similar initial hydroxylation catalytic efficiencies for 25-hydroxyvitamin D2 and calcifediol in the matched vesicle assay. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The two 25-hydroxy precursors were initially oxidized with similar enzyme efficiency. organism: Homo sapiens protein tissue_or_cell_type: phospholipid-vesicle membrane experimental_model: Matched recombinant human CYP24A1 initial-rate kinetics limitations: This is an enzyme comparison; it does not measure binding-protein clearance, repeated dosing, or whole-person serum responses. exposure: Comparative kcat/Km at low substrate availability; exact substrate range not reported in abstract. cross_nutrient: false evidence_location: Primary abstract: identified C24R products and comparative initial-rate kinetics. nutrient: Vitamin D2 and D3 [li2023] Inactivation of vitamin D2 metabolites by human CYP24A1. (2023). https://pubmed.ncbi.nlm.nih.gov/37495192/ DOI: 10.1016/j.jsbmb.2023.106368
    Complete structured claim and evidence

  2. Across both countries, mean tracer half-life was 13.9 days for 25(OH)D2 versus 15.1 days for 25(OH)D3 (P=0.001); the difference was significant in Gambians but not the UK subgroup.

    25-Hydroxyvitamin D2 → Plasma 25-hydroxyvitamin D2 tracer half-life source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    experimental_model
    Oral deuterated 25(OH)D2 and 25(OH)D3 tracer study; 18 Gambian and 18 UK healthy men
    exposure
    Oral deuterated 25(OH)D2 and 25(OH)D3, 40 nmol each; sampling 33 days.
    limitations
    Measured metabolites rather than parent supplements; country subgroup and DBP associations do not provide a universal whole-body storage half-life.
    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
    plain_language
    The circulating D2-derived metabolite cleared somewhat faster overall, with variation between groups.
    primary_references
    [jones2014] 25(OH)D2 half-life is shorter than 25(OH)D3 half-life and is influenced by DBP concentration and genotype. (2014). https://pubmed.ncbi.nlm.nih.gov/24885631/ DOI: 10.1210/jc.2014-1714
    tissue_or_cell_type
    Human circulating measurements

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1379–1390

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Oral deuterated 25(OH)D2 and 25(OH)D3 tracer study; 18 Gambian and 18 UK healthy men · source_derived_draft · unverified_draft

    ### vd-jones-half-life Across both countries, mean tracer half-life was 13.9 days for 25(OH)D2 versus 15.1 days for 25(OH)D3 (P=0.001); the difference was significant in Gambians but not the UK subgroup. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The circulating D2-derived metabolite cleared somewhat faster overall, with variation between groups. organism: Homo sapiens tissue_or_cell_type: Human circulating measurements experimental_model: Oral deuterated 25(OH)D2 and 25(OH)D3 tracer study; 18 Gambian and 18 UK healthy men limitations: Measured metabolites rather than parent supplements; country subgroup and DBP associations do not provide a universal whole-body storage half-life. exposure: Oral deuterated 25(OH)D2 and 25(OH)D3, 40 nmol each; sampling 33 days. cross_nutrient: false [jones2014] 25(OH)D2 half-life is shorter than 25(OH)D3 half-life and is influenced by DBP concentration and genotype. (2014). https://pubmed.ncbi.nlm.nih.gov/24885631/ DOI: 10.1210/jc.2014-1714
    Complete structured claim and evidence

What acts on it

  1. Recombinant human CYP2R1 hydroxylated ergocalciferol at C25 to form 25-hydroxyvitamin D2.

    Human vitamin D 25-hydroxylase / CYP2R1 → 25-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 enzyme product identification
    exposure
    D2 substrate incubations; detailed concentration/time not available in abstract.
    limitations
    A shared enzyme does not by itself prove equal long-term serum responses to all D2 and D3 dosing regimens.
    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
    The same first-step enzyme also activates D2.
    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
    microsomal enzyme preparation

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 302–315

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

    ### vd-act-cyp2r1-d2 Recombinant human CYP2R1 hydroxylated ergocalciferol at C25 to form 25-hydroxyvitamin D2. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The same first-step enzyme also activates D2. organism: Homo sapiens protein tissue_or_cell_type: microsomal enzyme preparation experimental_model: Recombinant human enzyme product identification limitations: A shared enzyme does not by itself prove equal long-term serum responses to all D2 and D3 dosing regimens. exposure: D2 substrate incubations; detailed concentration/time not available in 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

Where it participates (unsigned role)

  1. Human CYP24A1 initiated 25-hydroxyvitamin D2 oxidation by hydroxylation at C24R in the vesicle-reconstituted enzyme system.

    Vitamin D 24-hydroxylase / CYP24A1 → 24R,25-Dihydroxyvitamin D2 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary abstract: identified C24R products and comparative initial-rate kinetics.
    experimental_model
    Partially purified human CYP24A1 product analysis
    exposure
    25(OH)D2 substrate; concentration/time not specified in retrieved primary abstract.
    limitations
    Additional oxidation sites and products were not all fully identified; this is one identified initial route.
    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
    CYP24A1 begins one breakdown route for the D2 precursor.
    primary_references
    [li2023] Inactivation of vitamin D2 metabolites by human CYP24A1. (2023). https://pubmed.ncbi.nlm.nih.gov/37495192/ DOI: 10.1016/j.jsbmb.2023.106368
    tissue_or_cell_type
    phospholipid-vesicle membrane

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 512–525

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Partially purified human CYP24A1 product analysis · source_derived_draft · unverified_draft

    ### vd-act-cyp24a1-25d2 Human CYP24A1 initiated 25-hydroxyvitamin D2 oxidation by hydroxylation at C24R in the vesicle-reconstituted enzyme system. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: CYP24A1 begins one breakdown route for the D2 precursor. organism: Homo sapiens protein tissue_or_cell_type: phospholipid-vesicle membrane experimental_model: Partially purified human CYP24A1 product analysis limitations: Additional oxidation sites and products were not all fully identified; this is one identified initial route. exposure: 25(OH)D2 substrate; concentration/time not specified in retrieved primary abstract. cross_nutrient: false evidence_location: Primary abstract: identified C24R products and comparative initial-rate kinetics. nutrient: Vitamin D2 and D3 [li2023] Inactivation of vitamin D2 metabolites by human CYP24A1. (2023). https://pubmed.ncbi.nlm.nih.gov/37495192/ DOI: 10.1016/j.jsbmb.2023.106368
    Complete structured claim and evidence

  2. Human CYP27B1 1alpha-hydroxylated 25-hydroxyvitamin D2 in phospholipid vesicles; low-substrate catalytic efficiency was similar to that measured for calcifediol.

    Vitamin D 1-alpha-hydroxylase / CYP27B1 → 1-alpha,25-Dihydroxyvitamin D2 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary Tables 3-5, Figure 6A and Experimental procedures; full text retrieved.
    experimental_model
    Partially purified human CYP27B1 membrane assay
    exposure
    5-40 nM CYP27B1; 15 micromolar FDX1, 0.4 micromolar FDXR, 50 micromolar NADPH; 2 min at 37 C. Table 5/Figure 6A.
    limitations
    D2 kinetic data came from one experiment; results do not establish human dosing equivalence.
    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 proteins
    plain_language
    CYP27B1 completes activation of the D2 precursor.
    primary_references
    [tang2012] Expression of human CYP27B1 in Escherichia coli and characterization in phospholipid vesicles. (2012). https://pubmed.ncbi.nlm.nih.gov/22862690/ DOI: 10.1111/j.1742-4658.2012.08736.x
    tissue_or_cell_type
    reconstituted inner-mitochondrial-membrane model

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 437–450

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Partially purified human CYP27B1 membrane assay · source_derived_draft · unverified_draft

    ### vd-act-cyp27b1-d2 Human CYP27B1 1alpha-hydroxylated 25-hydroxyvitamin D2 in phospholipid vesicles; low-substrate catalytic efficiency was similar to that measured for calcifediol. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: CYP27B1 completes activation of the D2 precursor. organism: Homo sapiens proteins tissue_or_cell_type: reconstituted inner-mitochondrial-membrane model experimental_model: Partially purified human CYP27B1 membrane assay limitations: D2 kinetic data came from one experiment; results do not establish human dosing equivalence. exposure: 5-40 nM CYP27B1; 15 micromolar FDX1, 0.4 micromolar FDXR, 50 micromolar NADPH; 2 min at 37 C. Table 5/Figure 6A. cross_nutrient: false evidence_location: Primary Tables 3-5, Figure 6A and Experimental procedures; full text retrieved. nutrient: Vitamin D2 and D3 [tang2012] Expression of human CYP27B1 in Escherichia coli and characterization in phospholipid vesicles. (2012). https://pubmed.ncbi.nlm.nih.gov/22862690/ DOI: 10.1111/j.1742-4658.2012.08736.x
    Complete structured claim and evidence

  3. Serum collected after D2 treatment of low-status patients better supported TLR-triggered monocyte hCAP expression ex vivo.

    Ergocalciferol / vitamin D2 → Human CAMP mRNA source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    experimental_model
    Human bone-clinic cohort and ex-vivo monocytes in 10% autologous serum
    exposure
    D2 50, 000 IU twice weekly 5 weeks in low-status patients; paired serum used for ex-vivo assays.
    limitations
    Before/after serum comparison; no randomized D2/D3 head-to-head or demonstrated reduction of infections.
    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
    plain_language
    D2 treatment changed serum support for a local cell response.
    primary_references
    [adams2009] Vitamin d-directed rheostatic regulation of monocyte antibacterial responses. (2009). https://pubmed.ncbi.nlm.nih.gov/19299728/ DOI: 10.4049/jimmunol.0803736
    tissue_or_cell_type
    Patient serum and ex-vivo monocytes

    Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1009–1020

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human bone-clinic cohort and ex-vivo monocytes in 10% autologous serum · source_derived_draft · unverified_draft

    ### vd-adams-d2-serum-rescue Serum collected after D2 treatment of low-status patients better supported TLR-triggered monocyte hCAP expression ex vivo. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: D2 treatment changed serum support for a local cell response. organism: Homo sapiens tissue_or_cell_type: Patient serum and ex-vivo monocytes experimental_model: Human bone-clinic cohort and ex-vivo monocytes in 10% autologous serum limitations: Before/after serum comparison; no randomized D2/D3 head-to-head or demonstrated reduction of infections. exposure: D2 50, 000 IU twice weekly 5 weeks in low-status patients; paired serum used for ex-vivo assays. cross_nutrient: false [adams2009] Vitamin d-directed rheostatic regulation of monocyte antibacterial responses. (2009). https://pubmed.ncbi.nlm.nih.gov/19299728/ DOI: 10.4049/jimmunol.0803736
    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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