Vitamin D Levels Are Unrelated to the Severity of Respiratory Syncytial Virus Bronchiolitis Among Hospitalized Infants.
BACKGROUND
Vitamin D deficiency at birth has been reported as a risk factor for respiratory syncytial virus (RSV) lower respiratory tract infection during the first year of life. Limited data are available on whether an infant's vitamin D status is associated with the severity of acute RSV bronchiolitis.


METHODS
Infants < 1 year of age and hospitalized with their first episode of RSV bronchiolitis were enrolled into the RSV Bronchiolitis in Early Life II cohort. We investigated the relationships between vitamin D status at enrollment and the following indicators of bronchiolitis severity: duration of hospitalization, lowest oxygen saturation measured during hospitalization, and bronchiolitis severity score.


RESULTS
Among the 145 enrolled infants, the median (quartile 1 [Q1], Q3) serum 25-OH-VitD level was 36.8 (29.8, 42.3) ng/mL, with 14 infants (9.7%) having deficient serum vitamin D levels (25-OH-VitD <20 ng/mL). Vitamin D-deficient infants were younger than infants with 25-OH-VitD ≥ 20 ng/mL (2.8 vs 4.5 months, respectively; P = .04) and were less likely to consume infant's formula (42.9% vs 87.0%, respectively; P < .01). The following indicators of acute bronchiolitis severity did not differ between infants who were vitamin D-deficient and nondeficient: duration of hospitalization (P = .53), lowest oxygen saturation (P = .45), and bronchiolitis severity score (P = .97), even after adjusting for age, and for infant's formula consumption.


CONCLUSIONS
Among this cohort of infants that were hospitalized for RSV bronchiolitis, vitamin D status at the time of bronchiolitis was not associated with indicators of acute bronchiolitis severity.
Division of Pediatric Allergy, Immunology and Pulmonary Medicine, Department of Pediatrics ; and.
Avraham
A
Beigelman
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Mario
M
Castro
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Toni L
TL
Schweiger
Department of Biostatistics , Washington University School of Medicine ; St. Louis, Missouri.
Brad S
BS
Wilson
Department of Biostatistics , Washington University School of Medicine ; St. Louis, Missouri.
Jie
J
Zheng
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Huiquing
H
Yin-DeClue
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Geneline
G
Sajol
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Tusar
T
Giri
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Oscar L
OL
Sierra
Division of Pediatric Allergy, Immunology and Pulmonary Medicine, Department of Pediatrics ; and.
Megan
M
Isaacson-Schmid
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine ; and.
Kaharu
K
Sumino
Department of Biostatistics , Washington University School of Medicine ; St. Louis, Missouri.
Kenneth B
KB
Schechtman
Division of Pediatric Allergy, Immunology and Pulmonary Medicine, Department of Pediatrics ; and.
Leonard B
LB
Bacharier
D001990:Bronchiolitis, Viral / Q000150:complications / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000097:blood; D007223:Infant; D008297:Male; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000150:complications / Q000503:physiopathology*; D018113:Respiratory Syncytial Virus, Human; D012720:Severity of Illness Index; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000503:physiopathology
D007155:Immunologic Factors; D014807:Vitamin D
bronchiolitis; respiratory syncytial virus; vitamin D