Combining probiotics and vitamin D to reduce allergic rhinitis symptoms

Investigating Efficacy of Combined Probiotics and Vitamin D Supplementation in Reducing Symptoms and Improving Quality of Life in Patients With Allergic Rhinitis

Not applicable Interventional Tanta University · NCT07115342

This project will test whether taking probiotics and vitamin D together helps adults with allergic rhinitis have fewer symptoms and better quality of life.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment120 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorTanta University Academic / other
Locations1 site (Tanta, Gharbia Governorate)
Trial IDNCT07115342 on ClinicalTrials.gov

What this trial studies

This is a randomized, controlled, two-arm trial enrolling adults with moderate to severe allergic rhinitis and vitamin D insufficiency or deficiency. Participants will continue their usual allergic rhinitis treatments and be randomly assigned to receive either standard care alone or standard care plus daily probiotic capsules and vitamin D supplementation tailored to blood levels for 12 weeks. The study will measure symptom severity, quality of life using validated questionnaires, and changes in immune markers from clinic visits and lab tests. Results will show whether adding these accessible supplements offers measurable symptomatic and immunologic benefits.

Who should consider this trial

Good fit: Adults with a confirmed diagnosis of allergic rhinitis, persistent symptoms for at least two years, and vitamin D insufficiency or deficiency who can attend clinic visits and provide informed consent are ideal candidates.

Not a fit: People with mild or intermittent allergic rhinitis, normal vitamin D levels, current systemic corticosteroid or immunosuppressive use, or contraindications to probiotics or vitamin D are less likely to benefit from this intervention.

Why it matters

Potential benefit: If successful, adding probiotics and vitamin D to standard care could provide a low-risk, accessible way to reduce nasal and eye symptoms and improve quality of life for people with allergic rhinitis.

How similar studies have performed: Previous trials have reported modest benefits from probiotics or vitamin D when studied separately, but the combined effect of both supplements in allergic rhinitis remains largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Confirmed diagnosis of AR based on clinical history and specific IgE testing or will be screened for eligibility by the modified Mini Rhino-conjunctivitis Quality of Life Questionnaire (Mini RQLQ).

Persistent rhinitis symptoms for at least two consecutive years.

Presence of two or more AR symptom domains, including sneezing, watery rhinorrhea, nasal itching, and nasal congestion, with symptoms persisting or accumulating for more than 1 hour daily with \> 2 scores without taking medication.

Symptoms may be accompanied by ocular manifestations such as eye itching, tearing, and redness

Voluntarily and in writing, sign an informed consent form agreeing to participate in this study and able to complete the study as required by the trial protocol.

Vitamin D insufficiency or deficiency. Deficiency: \< 20 ng/mL (\< 50 nmol/L), Insufficiency: 20-29 ng/mL (50-75 nmol/L)

Exclusion Criteria:

Use of systemic corticosteroids, immunosuppressive therapy, or medications affecting the gut microbiota (antimicrobials, probiotics, prebiotics, intestinal mucosal protective agents, etc.) within 4 weeks prior to screening.

Regular use of probiotics, prebiotics, or vitamin D supplements within 6 months prior to screening.

History of or concurrent use of medications or supplements that alter serum 25(OH)D levels, such as barbiturates, bisphosphonates, sulfasalazine, anticonvulsants, antiretrovirals, omega-3 supplements, or ketoconazole.

Diagnosed with pulmonary tuberculosis, allergic asthma, chronic obstructive pulmonary disease (COPD), mast cell activation syndrome, or other respiratory diseases requiring treatment.

Coexisting conditions such as nasal polyps, severe nasal septum deviation, severe gastrointestinal diseases (e.g., severe diarrhea or inflammatory bowel diseases), metabolic syndrome (e.g., obesity, dyslipidemia, hypertension, diabetes), or chronic systemic diseases or malignancies.

History of autoimmune diseases or chronic inflammatory conditions.

Sinusitis, otitis media, or respiratory tract infections or upper respiratory infections within 14 days of the study start.

Known hypersensitivity or allergy to any component of the probiotics or other study interventions.

Physical signs or symptoms suggestive of renal, hepatic, or cardiovascular disease.

Pregnant or lactating women.

Where this trial is running

Tanta, Gharbia Governorate

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Allergic RhinitisNutritional SupplementationIntegrative MedicineVitamin D DeficiencyT Regulatory CellsTh2 InflammationImmune ResponseAnti-inflammatory
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.