Prevalence of Vitamin D Deficiency and Its Association with Recurrent Respiratory Infections in Children

Submission: 01 November 2025 | Acceptance: 20 January 2026 | Publication: 09 April 2026

Dr Farid Ullah¹, Dr Haroon Raja², Dr Kamran Safdar³, Dr Tahmoor Ghori⁴, Dr Zamin Abbas⁵, Dr Asad Jahangir⁶

¹Assistant Professor of Pediatrics DHQ Teaching Hospital MTI DIKHAN

²Senior Registrar, Shifa International Hospital, Islamabad

³Associate Professor, Jinnah Hospital, Lahore

⁴Professor of Medicine, Bolan Medical College, Quetta

⁵Associate Professor, Hayatabad Medical Complex, Peshawar

⁶Assistant professor, Dow University of Health Sciences, Karachi

ABSTRACT:

Background: Vitamin D deficiency had been recognized as a common nutritional problem in children and was increasingly associated with impaired immune function. Recurrent respiratory infections (RRIs) had been frequently reported in pediatric populations and were thought to be linked with low serum vitamin D levels.

Aim: The study aimed to determine the prevalence of vitamin D deficiency and its association with recurrent respiratory infections in children.

Methodology: This cross-sectional observational study was conducted at the Pakistan Institute of Medical Sciences (PIMS), Islamabad. A total of 90 children were enrolled over the study duration from May 2025 to April 2026. Serum vitamin D levels were measured and categorized as deficient, insufficient, or sufficient according to standard clinical thresholds. Clinical history was obtained to identify children with recurrent respiratory infections, defined as ≥3 episodes of upper or lower respiratory tract infections within the previous 12 months. Data were analyzed to assess the association between vitamin D status and frequency of respiratory infections.

Results: Vitamin D deficiency was observed in a substantial proportion of participants. A higher frequency of recurrent respiratory infections was noted among children with deficient vitamin D levels compared to those with sufficient levels. Statistical analysis revealed a significant association between low vitamin D status and increased risk of RRIs. Children with severe deficiency demonstrated the highest incidence of repeated infections, while those with adequate levels showed comparatively fewer episodes.

Conclusion: The study concluded that vitamin D deficiency had been highly prevalent among children and was significantly associated with recurrent respiratory infections. Early identification and correction of vitamin D deficiency could have contributed to reducing infection burden and improving pediatric immune health.

Keywords: Vitamin D deficiency, recurrent respiratory infections, children, immunity, prevalence, pediatric health.