RESUMO
BACKGROUND AND OBJECTIVE: Low serum 25-hydroxyvitamin D (25[OH]D) levels have been associated with increased susceptibility to and severity of respiratory viral infections. Hypovitaminosis D may be a modifiable risk factor in the severity of viral respiratory illnesses. The hypothesis for this study was that children hospitalized for respiratory illnesses would have lower serum 25(OH)D levels than controls and that 25(OH)D levels would be associated with illness severity among cases. METHODS: A case-control study of a sample of patients aged 6 months through 12 years hospitalized from January to May 2010 at an urban pediatric referral hospital was performed. Cases were children hospitalized for acute respiratory illnesses, and controls were children hospitalized for nonrespiratory illnesses. Illness severity among cases was assessed according to hospital length of stay, ICU admission, peripheral oxygen saturation, and pediatric risk of admission II score. Associations between serum 25(OH)D levels and dependent variables were tested for by using binary logistic and multivariable linear regression while controlling for admission diagnosis, age, gender, and race/ethnicity. RESULTS: The majority of cases (n = 38) and controls (n = 83) were African American (65.8% and 59.0%, respectively). Of the entire cohort (N = 121), 64.8% had vitamin D insufficiency (25[OH]D level ≤30 ng/mL) and 31.1% had vitamin D deficiency (25[OH]D level ≤20 ng/mL). Mean ± SD 25(OH)D levels did not differ between cases and controls (26.8 ± 11.5 vs 26.1 ± 10.6 ng/mL, respectively; P = .73). CONCLUSIONS: Hypovitaminosis D was common among cases and controls, but it was not significantly associated with the presence or severity of respiratory illnesses.
