Origin & tradition
Not traditional: vitamin D's role emerged from bone and endocrine science; sunlight is its natural source.
Western tradition · Vitamin
Vitamin D3 维生素 D3
A foundational hormone-vitamin where deficiency is common and consequential for aging health.
1,645ClinicalTrials.gov matched
2632PubMed RCT records
333Meta-analysis records
1+PubMed records
CholecalciferolKey active compound
Data definition. Matched records include all indexed medical endpoints for this intervention — not only longevity. Longevity-relevant records are screened separately and cited in the evidence summary below. Counts are matched-record volumes, not de-duplicated trials and not efficacy claims.
Why longevity buyers care
Key active: Cholecalciferol (vitamin D3).
Vitamin D regulates calcium, immune function, and gene expression; while megatrials (VITAL) were mixed on hard endpoints, deficiency correction supports bone, falls, and immune resilience in older adults — and recent work links it to telomere/biological-aging markers.
Effect summary
Studied health outcomes
Editorial summary — This table is curated by hand from published research consensus, not automatically calculated from our trial database. Grades reflect our interpretation of the literature. Treat as a starting point, not a definitive verdict. See the Evidence panel below for the underlying trial and paper counts sourced directly from ClinicalTrials.gov and PubMed.
| Health outcome | Effect | Magnitude | Grade |
|---|---|---|---|
| Bone mineral density | Increases | Moderate | A |
| Vitamin D deficiency correction | Increases | Strong | A |
| Respiratory infections | Decreases | Moderate | A |
| All-cause mortality (deficient populations) | Decreases | Minor | B |
| Muscle function in elderly | Increases | Minor | B |
| Cardiovascular events — Neutral in replete populations | No change | Negligible | B |
| Depression scores | Decreases | Minor | B |
Grade: A = robust RCTs · B = several RCTs / meta-analysis · C = limited or mixed RCTs · D = observational or early data
Dosage guidance
How Vitamin D3 is typically used
- Typical dose
- 1,000–4,000 IU/day (D3 form)
- Form
- softgel (D3 in oil) or chewable
- Timing
- with a fat-containing meal
Test 25(OH)D serum levels first; optimal range generally considered 40–60 ng/mL. D3 (cholecalciferol) is preferred over D2. Co-supplement with vitamin K2 (MK-7, 90–200 mcg) when using higher doses.
Informational only — not a prescription or personalised medical advice. Consult a qualified clinician before starting any supplement or medication.
Evidence summary
What the research actually says
79Evidence confidence
Extensive human-trial evidence2,632 randomized controlled trials · 333 meta-analyses / systematic reviews
Large RCTs (mixed on endpoints); deficiency correction matters
Vitamin D regulates calcium, immune function, and gene expression; while megatrials (VITAL) were mixed on hard endpoints, deficiency correction supports bone, falls, and immune resilience in older adults — and recent work links it to telomere/biological-aging markers.
1,645registered clinical trials reference this intervention
1selected from 1+ PubMed papers (longevity / aging angle)
Key active: Cholecalciferol (vitamin D3).
According to PubMed and ClinicalTrials.gov: trial counts from ClinicalTrials.gov, peer-reviewed literature from PubMed. Counts auto-refresh weekly; last checked 2026-07-19. They include trials across many endpoints, not only longevity.
Informational only — not medical advice, a treatment claim, or a substitute for a qualified clinician. Evidence strength varies; we show mixed and null results on purpose.
Evidence collections
Vitamin D3 appears in
Compare the evidence
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