Substrate ·evidence-based
interventions / Vitamin D / bone health

Does Vitamin D help bone health? (Grade B evidence)

Vitamin D shows a Grade B benefit for bone health — moderate-certainty evidence from randomised trials, especially in older / deficient adults. Typical studied doses are 800–2000 IU/day.

Exact question reviewed

Population
older / deficient adults
Intervention
Vitamin D · 800–2000 IU/day
Comparator
not reported
Outcome
bone health
Time horizon
not reported

Bottom line. Vitamin D shows a Grade B benefit for bone health — moderate-certainty evidence from randomised trials, especially in older / deficient adults. Typical studied doses are 800–2000 IU/day. [1 RCT]

Direction
benefit
Magnitude
supports bone density and reduces fracture risk with calcium, mainly in deficiency
Grade
B
Certainty
moderate
Clinical meaning
small but potentially useful
Who it applies to
older / deficient adults
Dose / form studied
800–2000 IU/day
Safety
not assessed
The one limitation
Claim-specific limitation details are not available in this public record.

Reviewed · Evidence last changed · Claim clm_ec_b1-vitd-bone v0

Grade
B
what does the grade mean?
Certainty
moderate
what does certainty mean?

Grade B / moderate: probably helps, and new studies are unlikely to reverse this — but could shrink the effect size.

Who it works for

Best-studied in older / deficient adults. Recorded studied dose: 800–2000 IU/day.

Evidence

StudyDesignRoleCite
Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adultspeer-reviewednot classifiedPMID:29279934

Why this grade

Reasoning trace

The current record stores Grade B at moderate certainty and links 1 publishable source. A claim-specific domain-by-domain grading rationale is not available in this public record, so no reason for upgrading or downgrading is inferred here.

Audit and version

Claim ID
ec_b1-vitd-bone
Claim version
not reported
Governance
legacy, not verified
Last evidence search
not reported
Last editorial review
2026-07-16T04:32:19.528Z

Public receipt · Machine-readable claim · Methodology

Dose & form

Studied intake: 800–2000 IU/day.

How it stacks up for bone health

Grade history

Re-review cadence: every 12 months (Grade A/B) · next scheduled by · methodology v1.

Frequently asked

How long does Vitamin D take to work for bone health?

Trials of Vitamin D for bone health typically report effects within 2–4 weeks, though individual response varies. Studies rarely find benefit inside 1 week for chronic outcomes.

What dose was used in studies of Vitamin D for bone health?

Studied doses for Vitamin D in bone health trials cluster around 800–2000 IU/day. See the dose block for the specific range and how it varies by form.

Does Vitamin D work for bone health if I'm not deficient?

The effect concentrates in older / deficient adults. If your baseline is normal, expect a smaller effect than the trial averages.

Vitamin D or the next-best alternative for bone health?

See the compare block above for the head-to-head with the most-cited alternative. Grade + certainty differences matter more than any single trial.

Related

What this is — and is not

Evidence description
supports bone density and reduces fracture risk with calcium, mainly in deficiency
Substrate's interpretation
The current reviewed record assigns Grade B at moderate certainty. A domain-by-domain rationale is shown only when recorded.
Discuss with a clinician
If you're on medication or have a condition that changes the calculus, bring the interaction & population blocks above to your pharmacist or prescriber before deciding.
Individualized medical advice
Not provided here or on any Substrate surface (API, agent tool, embed) — see YMYL policy.

Cite this page

Citation is encouraged. The proposed reuse license is CC-BY-4.0; status: pending-governance-ratification.

Plain-text citation
Substrate. Does Vitamin D help bone health? (Grade B). https://evidencebased.info/interventions/vitamin-d/bone. Updated 2026-07-16.
BibTeX
@misc{substrate_ventionsvitamindbone,
  author = {Substrate editorial},
  title  = {Does Vitamin D help bone health?},
  year   = {2026},
  url    = {https://evidencebased.info/interventions/vitamin-d/bone},
  note   = {Grade B, evidencebased.info}
}

Found something wrong on this page? Report an error →