Vitamin D Status and Asthma Control, Pulmonary Function, and Oxidative Stress in Adults With Bronchial Asthma (VD-ASTHMA)

July 26, 2026 updated by: Amany Gomaa Atiaa, Sinai University

Association Between Serum Vitamin D Status, Asthma Control, Pulmonary Function, and Oxidative Stress Biomarkers in Egyptian Adults With Bronchial Asthma: A Cross-Sectional Study

Asthma is a chronic inflammatory airway disease associated with variable airflow limitation and persistent respiratory symptoms. Vitamin D has been proposed as a potential biomarker related to immune regulation, asthma control, pulmonary function, and oxidative stress balance.

This prospective cross-sectional observational study aims to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations, asthma control, pulmonary function parameters, and erythrocyte oxidative stress biomarkers among Egyptian adults with bronchial asthma.

A total of 200 adult asthma patients will be recruited from Abbassia Chest Hospital, Cairo, Egypt. Participants will undergo clinical assessment, Asthma Control Test (ACT), post-bronchodilator spirometry, serum vitamin D measurement, and oxidative stress biomarker assessment including malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and reduced glutathione (GSH).

Participants will be categorized according to serum 25(OH)D concentrations into vitamin D deficient, insufficient, and sufficient groups.

No intervention or treatment assignment will be performed.

5. Detailed Description

Study Overview

Status

Not yet recruiting

Conditions

Detailed Description

This single-center cross-sectional observational study is designed to evaluate the association between serum vitamin D status and asthma-related clinical, functional, and biochemical characteristics among adult patients with bronchial asthma.

Eligible participants will be adults aged 18 years or older with confirmed bronchial asthma who are clinically stable at the time of assessment. Participants will be recruited from Abbassia Chest Hospital, Cairo, Egypt.

After obtaining written informed consent, demographic and clinical characteristics will be collected, including age, sex, body mass index (BMI), smoking status, asthma duration, previous exacerbations, hospitalization history, asthma severity, and current asthma medications including inhaled corticosteroids (ICS), long-acting β2 agonists (LABA), and short-acting β2 agonists (SABA).

Asthma control will be assessed using the Asthma Control Test (ACT), which evaluates symptom frequency, rescue medication use, activity limitation, and patient perception of asthma control.

Pulmonary function will be evaluated using post-bronchodilator spirometry according to ATS/ERS recommendations. The recorded parameters will include forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio.

Blood samples will be collected for serum 25(OH)D measurement using the DiaSorin LIAISON® 25 OH Vitamin D chemiluminescent immunoassay and assessment of oxidative stress biomarkers in erythrocyte hemolysates, including MDA, SOD, GPx, and GSH.

Participants will be classified according to vitamin D status:

Vitamin D deficient: <20 ng/mL Vitamin D insufficient: 20-30 ng/mL Vitamin D sufficient: >30 ng/mL

The primary objective is to determine whether serum vitamin D concentration is associated with asthma control. Secondary objectives include evaluating associations with pulmonary function and oxidative stress biomarkers.

Study Type

Observational

Enrollment (Estimated)

134

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of 200 adult patients with confirmed bronchial asthma recruited from Abbassia Chest Hospital, Cairo, Egypt. Eligible participants will be adults aged ≥18 years with stable asthma at the time of assessment. Participants will be categorized according to serum 25-hydroxyvitamin D [25(OH)D] concentrations into vitamin D deficient (<20 ng/mL), vitamin D insufficient (20-30 ng/mL), and vitamin D sufficient (>30 ng/mL) groups. Clinical characteristics, asthma control, pulmonary function, serum vitamin D status, and erythrocyte oxidative stress biomarkers will be assessed during a single study visit.

Description

Inclusion Criteria

  • Age ≥ 18 years.
  • Confirmed diagnosis of bronchial asthma.
  • Clinically stable at the time of assessment.
  • Availability of spirometry results.
  • Availability of laboratory investigations including serum 25(OH)D and oxidative stress biomarkers.

Exclusion Criteria

  • Other chronic pulmonary diseases.
  • Active respiratory infection.
  • Malignancy.
  • Significant renal or hepatic disease.
  • Pregnancy.
  • Current vitamin D supplementation.
  • Other conditions known to markedly influence oxidative stress status.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Vitamin D Deficient Group
Adults with bronchial asthma and serum 25-hydroxyvitamin D concentrations below 20 ng/mL.
Vitamin D Insufficient Group
Adults with bronchial asthma and serum 25-hydroxyvitamin D concentrations between 20 and 30 ng/mL.
Vitamin D Sufficient Group
Adults with bronchial asthma and serum 25-hydroxyvitamin D concentrations above 30 ng/mL.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Asthma Control Level Measured by Asthma Control Test (ACT) Score
Time Frame: Single baseline assessment.
Assessment of asthma control using the Asthma Control Test (ACT) questionnaire, reported as an ACT score ranging from 0 to 25 points.
Single baseline assessment.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pulmonary Function Parameters
Time Frame: Single baseline assessment.
FEV1 % predicted FVC % predicted FEV1/FVC ratio
Single baseline assessment.
Oxidative Stress Biomarkers
Time Frame: Single baseline assessment.
Malondialdehyde (MDA) Superoxide dismutase (SOD) Glutathione peroxidase (GPx) Reduced glutathione (GSH)
Single baseline assessment.
Serum Vitamin D Concentration
Time Frame: Single baseline assessment.
Serum 25-hydroxyvitamin D concentration (ng/mL)
Single baseline assessment.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sinai University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 26, 2026

Primary Completion (Estimated)

December 30, 2026

Study Completion (Estimated)

February 25, 2027

Study Registration Dates

First Submitted

July 22, 2026

First Submitted That Met QC Criteria

July 26, 2026

First Posted (Actual)

July 29, 2026

Study Record Updates

Last Update Posted (Actual)

July 29, 2026

Last Update Submitted That Met QC Criteria

July 26, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB00014233-38

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be publicly shared. The datasets contain potentially identifiable health information, and participant consent and institutional ethical approval did not include unrestricted public data sharing. Reasonable requests for access to de-identified data may be considered by the corresponding author, subject to institutional and ethical approval.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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