Association of Vitamin D Level in Hyperreactive Airway Diseases: A Case-Control Study

Low vitamin D levels have been associated with hyperreactive airway diseases (HRADs) such as wheeze-associated lower respiratory tract infections, asthma, and allergic rhinitis in children. Vitamin D insufficiency is a modifiable risk factor for managing recurrent respiratory tract infections. This study aimed to estimate vitamin D levels in HRAD patients and assess their association with HRAD by comparing them to healthy children.

This case-control study was conducted over 18 months in the Department of Paediatrics, Guru Gobindsingh Government Hospital, Jamnagar. A total of 200 children (100 cases with HRADs and 100 healthy controls) aged six months to 12 years were enrolled using simple random sampling. Cases included children with ≥2 episodes of wheeze-associated lower respiratory tract infections or asthma. Controls were healthy children who were not taking vitamin D3 supplements attending the immunization clinic. Vitamin D levels were measured using electrochemiluminescence immunoassay (ECLIA). Data on dietary habits, sun exposure, and nutritional status were collected. Chest and wrist X-rays were evaluated.

The mean vitamin D level in cases (30.2 ± 17.8 ng/mL) was lower than that of controls (33.6 ± 14.5 ng/mL), with significantly higher odds of deficiency in cases (OR 3.31, p = 0.001). Vitamin D deficiency was associated with younger age, poor nutritional status, limited sun exposure, and low dietary intake of vitamin D-rich foods. Chest X-ray hyperinflation and wrist X-ray findings were significantly linked to vitamin D deficiency.

Vitamin D deficiency is significantly associated with HRADs in children. Screening and prophylaxis for vitamin D deficiency, particularly in at-risk groups, may help manage HRADs effectively.