Related Experiment Video
Updated: May 16, 2026
A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Vitamin D3 supplementation in patients with frequent respiratory tract infections: a randomised and double-blind
Peter Bergman1, Anna-Carin Norlin, Susanne Hansen
1Department of Laboratory Medicine, Clinical Microbiology, Karolinska Institutet, Stockholm, Sweden.
Background:
Low serum levels of 25-hydroxyvitamin D(3) are associated with an increased risk of respiratory tract infections (RTIs). Clinical trials with vitamin D(3) against various infections have been carried out but data are so far not conclusive. Thus, there is a need for additional randomised controlled trials of effects of vitamin D(3) on infections.
Objective:
To investigate if supplementation with vitamin D(3) could reduce infectious symptoms and antibiotic consumption among patients with antibody deficiency or frequent RTIs.
Design:
A double-blind randomised controlled trial.
Setting:
Karolinska University Hospital, Huddinge.
Participants:
140 patients with antibody deficiency (selective IgA subclass deficiency, IgG subclass deficiency, common variable immune disorder) and patients with increased susceptibility to RTIs (>4 bacterial RTIs/year) but without immunological diagnosis.
Intervention:
Vitamin D(3) (4000 IU) or placebo was given daily for 1 year.
Primary And Secondary Outcome Measures:
The primary endpoint was an infectious score based on five parameters: symptoms from respiratory tract, ears and sinuses, malaise and antibiotic consumption. Secondary endpoints were serum levels of 25-hydroxyvitamin D(3), microbiological findings and levels of antimicrobial peptides (LL-37, HNP1-3) in nasal fluid.
Results:
The overall infectious score was significantly reduced for patients allocated to the vitamin D group (202 points) compared with the placebo group (249 points; adjusted relative score 0.771, 95% CI 0.604 to 0.985, p=0.04).
Limitations:
A single study centre, small sample size and a selected group of patients. The sample size calculation was performed using p=0.02 as the significance level whereas the primary and secondary endpoints were analysed using the conventional p=0.05 as the significance level.
Conclusions:
Supplementation with vitamin D(3) may reduce disease burden in patients with frequent RTIs.
Related Concept Videos
01:29Acute Respiratory Failure-V
Ensure that patients are monitored continuously for their response to therapy, including changes in...
01:23Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
01:29Microbiota of the Respiratory Tract
01:28Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include:
01:30Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed.
01:22Connective Tissue Cell Types
Fat cells (adipocytes), smooth muscle cells (myoblasts), and bone cells (osteoblasts) are some connective tissue cell types. Some immune system cells...