Vitamin D clinical trials for Long COVID, ME/CFS and post-viral illness (3 trials, updated October 2026)

Name: OSMF post-viral clinical trials dataset (Long COVID, ME/CFS, post-viral overlap)
Creator: Open Source Medicine Foundation
License: https://creativecommons.org/licenses/by/4.0/

Research Tracker › Clinical trials › By agent › Vitamin D

Last updated 07 October 2026 from ClinicalTrials.gov. Trial statuses are refreshed automatically; check the registry record for the latest status and contact details.

3 trials0 open to enrolment2 completed1 unknown status

All interventional trials in our ClinicalTrials.gov extract that list Vitamin D as an intervention, across Long COVID / PASC (2), Unspecified / Overlap (1). 0 are currently open to enrolment and 2 have completed. Read the OSMF evidence profile for Vitamin D for literature, mechanism and dosing context.

Intervention names are normalised from the registry's own arm labels, so the same compound can appear under a brand name, a generic name or a combination; check the full agent index for related entries.

⚠️

Not medical advice. This page is an automatically compiled index of entries on ClinicalTrials.gov. Listing here is not an endorsement of any trial, sponsor or treatment, and trial status can change between our refreshes. Always confirm details on ClinicalTrials.gov and discuss participation with your own clinician.

Completed (2)

The Roles of Vitamin D and Microbiome in Children With Post-acute COVID-19 Syndromes (PACS) and Long COVID

CompletedPhase not applicable NCT05633472

Sponsor: China Medical University Hospital (Academic / non-profit / other)

Intervention(s): Vitamin D

Condition group: Long COVID / PASC

Start: Oct 2022 | Primary completion: Aug 2024 | Enrollment: 33 (actual)

Record last updated: Apr 2025

A double-blind study to evaluate the role of human microbiome and vitamin D in the development of long COVID and PACS in children.

View on ClinicalTrials.gov ↗

Magnesium and Vitamin D Combination for Post-COVID Syndrome

CompletedPhase not applicable NCT05630339

Sponsor: Coordinación de Investigación en Salud, Mexico (Other government)

Intervention(s): Magnesium Chloride, Vitamin D

Condition group: Long COVID / PASC

Start: Jan 2022 | Primary completion: May 2023 | Enrollment: 150 (actual)

Record last updated: Sep 2023

The goal of this double-blind randomized controlled clinical trial is to determine the efficacy of the administration of magnesium chloride + vitamin D as an adjuvant in the treatment of post-Coronavirus Disease (COVID) syndrome.

View on ClinicalTrials.gov ↗

Unknown status (1)

The Immune and Clinical Impacts of Vitamin D in Patients With Chronic Musculo-skeletal Pain

Unknown statusPhase 4 NCT01417923

Sponsor: Meir Medical Center (Academic / non-profit / other)

Intervention(s): Vitamin D

Condition group: Unspecified / Overlap

Start: Sep 2011 | Primary completion: Dec 2012 | Enrollment: 80 (estimated)

Record last updated: Nov 2012

Vitamin D3 is produced in the skin following exposure to UVB light from the sun or artificial sources, and occurs naturally in a small range of foods.More recently, several reports underlined the impact of vitamin D on the prevalence and consequences of inadequate vitamin D intake and the research supporting its benefits for alleviating chronic musculoskeletal pain and fatigue syndromes in outpatients.

View on ClinicalTrials.gov ↗

Frequently asked questions

How do I join a clinical trial?

Open the trial's ClinicalTrials.gov record (the "View on ClinicalTrials.gov" button), read the Eligibility Criteria and Contacts and Locations sections, and contact the study team listed there. Trials only enrol at the sites shown in the record, so check whether a site is near you or whether the study is remote/decentralised. Your own clinician can help you judge whether a trial is a sensible option and may need to provide medical records.

What do the trial phases mean?

Early Phase 1 / Phase 1 studies test safety and dosing in a small group. Phase 2 studies look for a signal of benefit in a larger group and keep checking safety. Phase 3 studies are large confirmatory trials designed to show whether a treatment works well enough for approval. Phase 4 studies follow approved treatments after they reach the market. "Phase not applicable" is used by the registry for behavioural, device, rehabilitation and other non-drug interventions.

Does the Open Source Medicine Foundation run these trials?

No. OSMF does not sponsor, run or recruit for any trial on this page. We compile public registry entries from ClinicalTrials.gov so patients and clinicians can find them in one place. For questions about a specific study, contact the sponsor or study team listed on its ClinicalTrials.gov record.

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Cite this page
Open Source Medicine Foundation. Vitamin D clinical trials for Long COVID, ME/CFS and post-viral illness (3 trials, updated October 2026). Research Tracker, 07 October 2026. https://research.opensourcemed.info/trials/by-agent/vitamin-d.html
Underlying dataset (JSON, CC BY 4.0): https://research.opensourcemed.info/data/clinical_trials/clinical_trials_current.json. Source records: ClinicalTrials.gov.