Disease × agent evidence record

Vitamin D for Long COVID: evidence, trials and status

Vitamin D has both completed registered trials and synthesis-level publications linked to Long COVID. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit.

2 registered trials 0 recruiting 34 publications Evidence tier C · Preliminary Score 40.0
Research Tracker › Pairs › Long COVID › Vitamin D
Research map, not treatment advice. This page aggregates registry and literature records. It does not evaluate efficacy, dosing or safety for any individual. Discuss any treatment decision with a qualified clinician.

Summary

Vitamin D is tracked by OSMF as an investigational option for Long COVID; no regulator has approved it for this indication, and most post-viral conditions have no approved disease-modifying therapy at all. ClinicalTrials.gov lists 2 registered trials linking Vitamin D to Long COVID: 2 have completed. None of the registered studies carries a drug-development phase label, which is typical for behavioural, device and supplement protocols. It plans or enrolled 150 participants. Registered activity dates to 2022. The literature layer holds 34 publications for this pair: 3 systematic reviews, 5 clinical trial publications, 17 PubMed search records and 9 other publications. The dated items are from 2026. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.

Long COVID / PASC is tracked on the OSMF post-viral programme alongside ME/CFS, Long COVID, POTS and MCAS. Across the programme, 423 candidate agents are logged for Long COVID, most of them preliminary; this page isolates the record for one of them.

Open in Repurposing ExplorerAgent page: Vitamin DLong COVID hubLong COVID biomarkers & interventionsPubChem

Evidence table

Evidence tierC · Preliminary
Evidence score40.0 (trials 5.0, literature 30.0, tier 5, approved bonus 0.0)
Registered trials2 total: 0 recruiting, 0 active / not yet recruiting, 2 completed, 0 other
Linked publications34 (17 PubMed search records, 9 other publications, 5 clinical trial publications, 3 systematic reviews)
Agent typeSupplement (Supplement / Nutraceutical)
Development stage (any indication)Investigational
Mechanism / classNot recorded
Data sourcesOSMF therapeutic agent database, ClinicalTrials.gov, PubMed
How the evidence score is calculated
  • Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
  • Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
  • The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
  • Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
  • The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.

Registered clinical trials

NCT IDTitleStatusPhaseEnrolment
NCT05633472The Roles of Vitamin D and Microbiome in Children With Post-acute COVID-19 Syndromes (PACS) and Long COVID
China Medical University Hospital · 2022
completedNot applicable33
NCT05630339Magnesium and Vitamin D Combination for Post-COVID Syndrome
Coordinación de Investigación en Salud, Mexico · 2022
completedNot applicable150

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Published literature

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Mechanism and notes

No mechanism of action is recorded for this pair in the source databases.

Clinical notes: Investigational for listed conditions. 2 associated trial(s) and 0 study reference(s) in current data. Review primary sources and consult specialists before use.

Safety: Limited specific safety data in these populations. Review full prescribing information and consult specialist. Many agents used off-label or investigational.

Dosing in studies: See linked studies/trials for reported doses and durations; typical protocols vary widely.

Frequently asked questions

Is Vitamin D approved for Long COVID?

Vitamin D is tracked by OSMF as an investigational option for Long COVID; no regulator has approved it for this indication, and most post-viral conditions have no approved disease-modifying therapy at all. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.

Is Vitamin D in clinical trials for Long COVID?

ClinicalTrials.gov lists 2 registered trials linking Vitamin D to Long COVID: 2 have completed. None of the registered studies carries a drug-development phase label, which is typical for behavioural, device and supplement protocols. It plans or enrolled 150 participants. Registered activity dates to 2022.

What does the evidence show for Vitamin D in Long COVID?

Vitamin D has both completed registered trials and synthesis-level publications linked to Long COVID. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is C (Preliminary), taken from the OSMF therapeutic agent database, which grades agents by the volume and design of condition-specific evidence rather than by effect size.

Cite this page

Open Source Medicine Foundation. Vitamin D for Long COVID: evidence, trials and status. OSMF Research Tracker. Updated 2026-10-07. https://research.opensourcemed.info/pairs/long-covid/vitamin-d.html

Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-10-07. Page built 2026-10-07.

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This is a research map, not treatment advice. Evidence tiers and scores summarise what has been studied, not whether a treatment works or is safe for you.