COVIDNCT04394390
Vitamin D Levels in SARS-CoV-2: Do Current Adequacy Thresholds Reflect Clinical Risk? Insights From a Large Turkish Cohort
An observational study of COVID and Vitamin D Deficiency, run by Bursa City Hospital at 1 site in Turkey (Türkiye).
Trial summary
Blood vitamin D levels may be associated with severity of viral infections. To find out If there is a statistically significant relation between blood 25-hydroxy vitamin D (25(OH)D) levels and disease severity, patients with Covid-19 viral infection were investigated. Read more about this study
- Who is it for?
- Ages 20 to 80 years
- Conditions the study is for
- COVID, Vitamin D Deficiency
- What is being tested?
- vitamin d
- How many people
- 1,100 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 May 2020to 30 Aug 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: 1100 confirmed COVİD-19 patients (PCR)
To find out vitamin D levels and it's relation with the disease severity serum 25-hydroxy-vitamin D levels, 1100 confirmed Covid-19 patients with available laboratory findings were included.
Exlucion Criterias:
Using immunsuppresan medical treatment. Using vitamin D or replacement history of vitamin D in last 3 months. Patients with malnutrition, immun deficiency, chronic infections, chronic other diseases such as rheumatoid arthritis, ankylosing spondilitis, lupus, hemplegia, paraplegia etc.
Trial locations and contacts
1 site in 1 country.
About this study
Blood vitamin D levels may be associated with severity of viral infections. To find out If there is a statistically significant relation between blood 25-hydroxy vitamin D (25(OH)D) levels and disease severity, patients with Covid-19 viral infection were investigated.
Read the detailed description
Purpose:
Vitamin D a steroid hormone has profound effects on human immunity. Active vitamin D, 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the 'oxidative burst' potential of macrophages. Epidemiological data has linked vitamin D deficiency to increased susceptibility to acute viral respiratory infections.
There is evidence that some patients with severe COVID-19 experience a cytokine storm with production of large quantities of interleukins, specifically IL-1 and IL-6. Moreover it was hipotiesied that the sufficient vitamin D levels may help to decrease IL-6 levels like tocizulamab which is a potent blocking agent of the IL-6 receptor.
In this observational study, possible relation between the disease and vitamin D levels were investigated in COVİD-19 patients.
Material and Methods:
To find out vitamin D levels and it's relation with the disease severity serum 25-hydroxy-vitamin D levels will be measured in nearly 1100 confirmed COVİD-19 patients. Same patients will also be evaluated for vital signs, laboratory and pulmoner CT findings. Demographic and medical data will also be collected. Statically significant positive or negative results and the comparison of these findings will be presented.
Presenting blood vitamin- D levels and it's possible assosiation with disease severity may inspire new perspectives for future trials spesifically focusing vitamin D levels.
- Conditions
- COVID, Vitamin D Deficiency
- Being tested
- vitamin d
- Keywords
- covid-19, infection, vitamin D, prevention
- Medical subject headings
- Vitamin D Deficiency, COVID-19, Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
vitamin dDietary supplement
Also called vitamin D levels
vitamin D levels
What is being measured
The primary outcome is the main question the study is designed to answer.
laboratory measured vitamin D levels
serum 25-hydroxy-vitamin D levels
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 May 2020
- Study start1 May 2020
- Primary completion15 May 2021
- Study completion30 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for COVIDStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Retrospective
- Enrolment
- 1,100 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bursa City Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Taner Dandinoğlu, Bursa City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04394390
- Sponsor's protocol ID
- 2020-PMR-1
- Status last verified
- Feb 2026
- First submitted
- 18 May 2020
- Last updated
- 5 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Research data will be available upon request from authors (Taner Dandinoglu MD. e-mail: dandinoglu@gmail.com, Sinem Akselim MD e-mail: sinemakselim@gmail.com)
Publications
Jayawardena R, Sooriyaarachchi P, Chourdakis M, Jeewandara C, Ranasinghe P. Enhancing immunity in viral infections, with special emphasis on COVID-19: A review. Diabetes Metab Syndr. 2020 Jul-Aug;14(4):367-382. doi: 10.1016/j.dsx.2020.04.015. Epub 2020 Apr 16.
PubMed 32334392Silberstein M. Vitamin D: A simpler alternative to tocilizumab for trial in COVID-19? Med Hypotheses. 2020 Jul;140:109767. doi: 10.1016/j.mehy.2020.109767. Epub 2020 Apr 23.
PubMed 32353742
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vitamin D Levels in SARS-CoV-2: Do Current Adequacy Thresholds Reflect Clinical Risk? Insights From a Large Turkish Cohort
- ClinicalTrials.gov ID
- NCT04394390
- Acronym / sponsor ID
- 2020-PMR-1
- Conditions
- COVID, Vitamin D Deficiency
- Keywords
- covid-19, infection, vitamin D, prevention
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 1,100 participants (actual)
- Lead sponsor
- Bursa City HospitalOther government
- Study start
- 1 May 2020 (actual)
- Primary completion
- 15 May 2021 (actual)
- Study completion
- 30 Aug 2025 (actual)
- First posted
- 19 May 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Blood vitamin D levels may be associated with severity of viral infections. To find out If there is a statistically significant relation between blood 25-hydroxy vitamin D (25(OH)D) levels and disease severity, patients with Covid-19 viral infection were investigated.
Detailed description
Purpose:
Vitamin D a steroid hormone has profound effects on human immunity. Active vitamin D, 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the 'oxidative burst' potential of macrophages. Epidemiological data has linked vitamin D deficiency to increased susceptibility to acute viral respiratory infections.
There is evidence that some patients with severe COVID-19 experience a cytokine storm with production of large quantities of interleukins, specifically IL-1 and IL-6. Moreover it was hipotiesied that the sufficient vitamin D levels may help to decrease IL-6 levels like tocizulamab which is a potent blocking agent of the IL-6 receptor.
In this observational study, possible relation between the disease and vitamin D levels were investigated in COVİD-19 patients.
Material and Methods:
To find out vitamin D levels and it's relation with the disease severity serum 25-hydroxy-vitamin D levels will be measured in nearly 1100 confirmed COVİD-19 patients. Same patients will also be evaluated for vital signs, laboratory and pulmoner CT findings. Demographic and medical data will also be collected. Statically significant positive or negative results and the comparison of these findings will be presented.
Presenting blood vitamin- D levels and it's possible assosiation with disease severity may inspire new perspectives for future trials spesifically focusing vitamin D levels.
Study design
- Observational model
- Case only
- Time perspective
- Retrospective
Who may qualify
- Ages
- 20 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- 1100 confirmed COVİD-19 patients (PCR)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| vitamin dAlso: vitamin D levelsvitamin D levels | Dietary supplement | – |
Primary outcome
laboratory measured vitamin D levels
Time frame: 12 months
serum 25-hydroxy-vitamin D levels
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Feb 2026.
- Background: PubMed 32334392Jayawardena R, Sooriyaarachchi P, Chourdakis M, Jeewandara C, Ranasinghe P. Enhancing immunity in viral infections, with special emphasis on COVID-19: A review. Diabetes Metab Syndr. 2020 Jul-Aug;14(4):367-382. doi: 10.1016/j.dsx.2020.04.015. Epub 2020 Apr 16.
- Background: PubMed 32353742Silberstein M. Vitamin D: A simpler alternative to tocilizumab for trial in COVID-19? Med Hypotheses. 2020 Jul;140:109767. doi: 10.1016/j.mehy.2020.109767. Epub 2020 Apr 23.
- Individual participant dataSharing planned: Undecided. Research data will be available upon request from authors (Taner Dandinoglu MD. e-mail: dandinoglu@gmail.com, Sinem Akselim MD e-mail: sinemakselim@gmail.com)
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID and Vitamin D Deficiency, run by Bursa City Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
laboratory measured vitamin D levels (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04394390, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Feb 2026.