Subnormal levels of vitamin D are associated with acute wheeze in young children.
OBJECTIVE
This study evaluated risk factors for acute wheeze in preschool children and investigated whether subnormal levels of vitamin D were associated with increased risk for acute wheeze, atopy or viral/bacterial respiratory infections.


METHODS
We recruited 130 children with acute wheeze, aged 6 months to 4 years, from paediatric emergency departments in Stockholm, Sweden, and 101 age-matched controls with no history of wheeze or sensitisation to airborne allergens. Parents answered standardised questionnaires, and blood samples were analysed for specific IgE to airborne and food allergens and levels of 25 hydroxyvitamin D (25(OH)D). Nasopharyngeal virus samples were collected during the emergency department visit in the group of children with wheeze, and a subset were also tested for bacteria.


RESULTS
Vitamin D insufficiency (25(OH)D < 75 nmol/L (30 ng/mL)) was associated with an odds ratio of 2.7 (95% confidence interval 1.1-6.2) for acute wheeze. However, no association was found between vitamin D insufficiency and atopy, presence of virus or bacteria or recurrent infections. Children older than 24 months were particularly at risk of subnormal vitamin D levels, irrespective of wheezing history.


CONCLUSIONS
Our findings support the hypothesis that subnormal levels of vitamin D are associated with acute wheeze in young children.
Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden; Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
Katarina
K
Stenberg Hammar
Gunilla
G
Hedlin
Jon R
JR
Konradsen
Björn
B
Nordlund
Inger
I
Kull
Christian G
CG
Giske
Christophe
C
Pedroletti
Cilla
C
Söderhäll
Erik
E
Melén
D016022:Case-Control Studies; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008019:Life Style; D016015:Logistic Models; D008297:Male; D012008:Recurrence; D012130:Respiratory Hypersensitivity / Q000097:blood / Q000209:etiology*; D012135:Respiratory Sounds / Q000209:etiology*; D012141:Respiratory Tract Infections / Q000097:blood / Q000821:virology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D014807:Vitamin D; C104450:25-hydroxyvitamin D
25-hydroxyvitamin D; Acute wheeze; Atopy; Infections; Preschool children; Virus