Component
Serum 25-hydroxyvitamin D2 concentration
Study-defined Serum 25-hydroxyvitamin D2 concentration. Read each linked record for species, exposure and endpoint.
1 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
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.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
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.
What acts on it
At day 28, D3 produced a 9.8 nmol/L greater decline in 25(OH)D2 than placebo (95% CI5.2–14.4); by day 56 the 1.7 nmol/L difference was not significant (CI−7.6–11.1).
Experimental context and source evidence
- cross_nutrient
- false
- experimental_model
- Two randomized single-dose experiments; 100 volunteers, 97 analyzed
- exposure
- Study 2: D2 50, 000 IU preload; four days later D3 50, 000 IU or placebo.
- limitations
- No direct enzyme-flux assay. Reciprocal fraction changes are not proof that D2 is toxic or that net total vitamin D falls.
- 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 reverse effect also occurred after D3, and its between-group difference was shorter-lived.
- primary_references
- [hammami2019] Vitamin-D2 treatment-associated decrease in 25(OH)D3 level is a reciprocal phenomenon: a randomized controlled trial. (2019). https://pubmed.ncbi.nlm.nih.gov/30658603/ DOI: 10.1186/s12902-019-0337-8
- tissue_or_cell_type
- Human circulating measurements
Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1418–1429
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Two randomized single-dose experiments; 100 volunteers, 97 analyzed · source_derived_draft · unverified_draft
### vd-hammami-d3-decreases-d2 At day 28, D3 produced a 9.8 nmol/L greater decline in 25(OH)D2 than placebo (95% CI5.2–14.4); by day 56 the 1.7 nmol/L difference was not significant (CI−7.6–11.1). Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The reverse effect also occurred after D3, and its between-group difference was shorter-lived. organism: Homo sapiens tissue_or_cell_type: Human circulating measurements experimental_model: Two randomized single-dose experiments; 100 volunteers, 97 analyzed limitations: No direct enzyme-flux assay. Reciprocal fraction changes are not proof that D2 is toxic or that net total vitamin D falls. exposure: Study 2: D2 50, 000 IU preload; four days later D3 50, 000 IU or placebo. cross_nutrient: false [hammami2019] Vitamin-D2 treatment-associated decrease in 25(OH)D3 level is a reciprocal phenomenon: a randomized controlled trial. (2019). https://pubmed.ncbi.nlm.nih.gov/30658603/ DOI: 10.1186/s12902-019-0337-8
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.