Maternal vitamin D intake during pregnancy is inversely associated with asthma and allergic rhinitis in 5-year-old children.
BACKGROUND
Vitamin D is known to have a number of immunological effects and it may play a role in preventing allergic diseases. Objectives To study the effect of maternal intake of vitamin D during pregnancy on the emergence of asthma, allergic rhinitis (AR), and atopic eczema by the age of 5 years in children with HLA-DQB1-conferred susceptibility for type 1 diabetes.


METHODS
Children (1669) participating in the population-based birth cohort study were followed for asthma, AR, and atopic eczema assessed by validated questionnaire at 5 years. Maternal diet was assessed by a food-frequency questionnaire.


RESULTS
The mean maternal intake of vitamin D was 5.1 (SD 2.6) microg from food and 1.4 (2.6) microg from supplements. Only 32% of the women were taking vitamin D supplements. When adjusted for potential confounders, maternal intake of vitamin D from food was negatively related to risk of asthma [hazard ratio (HR) 0.80; 95% confidence interval (CI) 0.64-0.99] and AR [HR 0.85; 95% CI 0.75-0.97]. Vitamin D supplements alone were not associated with any outcome. Adjustment for maternal intake of other dietary factors did not change the results.


CONCLUSIONS
Maternal vitamin D intake from foods during pregnancy may be negatively associated with risk of asthma and AR in childhood.
Erkkola
M
M
Division of Nutrition, Department of Applied Chemistry and Microbiology, University of Helsinki, Helsinki, Finland. maijaliisa.erkkola@helsinki.fi
Kaila
M
M
Nwaru
B I
BI
Kronberg-Kippilä
C
C
Ahonen
S
S
Nevalainen
J
J
Veijola
R
R
Pekkanen
J
J
Ilonen
J
J
Simell
O
O
Knip
M
M
Virtanen
S M
SM
D000328:Adult; D001249:Asthma / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D002675:Child, Preschool; D015331:Cohort Studies; D003876:Dermatitis, Atopic / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006683:HLA-DQ Antigens / Q000276:immunology; D059866:HLA-DQ beta-Chains; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011247:Pregnancy; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology
D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D014807:Vitamin D