Objective: Reduced maternal levels of vitamin D, E and zinc during pregnancy has been linked to the development of asthma and allergic disease in children. The birth cohort investigated if maternal dietary intake in pregnant Saudi women was associated with childhood asthma and allergic disease up to 24 months of age. Methods: One thousand six hundred and twenty four women were recruited to a prospective birth cohort from an antenatal clinic in Riyadh, Saudi Arabia. A food frequency questionnaire was used to characterize diet during pregnancy and serum micronutrient levels were measured. 1436 singleton children were followed up at 6, 12 and 24 months of age by interview administrated telephone calls. Results: Multivariate analyses revealed no associations between the primary maternal dietary nutrient intakes of vitamin E and zinc and the respiratory outcomes in the cohort children at 24 months of age. There was a borderline significant association between increasing maternal zinc intake and maternal reports of food allergy in the cohort children at 24 months. Positive associations with maternal dietary folate intake with maternally reported ‘itchy rash for at least 6 consecutive months' (OR= 2.36 p-=0.020) and any food allergies (OR= 2.18 p= 0.025). Conclusion: This study suggests no conclusive evidence that maternal intake of vitamin D, E and zinc of Saudi women may lower the risks of developing asthma and allergic disease in early childhood. However, a higher dietary intake of folate during pregnancy increased the risk of reported itchy rash, eczema and food allergy in the cohort children up to 24 months. Further follow up of the cohort will provided evidence that will support or refute whether maternal diet during pregnancy is associated with asthma and allergic disease in childhood.

The SEATON cohort comprising 2000 pregnant women recruited 1997-99 was established to test if maternal nutrition during pregnancy affects the likelihood of children developing asthma. At 32 weeks gestation mothers’ diets were assessed by food frequency questionnaire. 1,924 live singleton births comprised the birth cohort with follow-up at 6 months, 1, 2, 5 and 10 years (the latter the focus of this thesis). Children’s diets were assessed at 5 and 10 years. Their asthmatic status was assessed by International Study of Asthma and Allergies in Childhood questionnaire. Children participating at 5 or 10 years were also invited for measurement of spirometry and allergy. Cross-sectionally at 10 years 934 children (48% boys) participated by return of questionnaire, 449 also took part in the in-depth assessment. Higher maternal vitamin D intakes were associated with decreased odds of ‘doctor diagnosed asthma’, ‘wheeze ever’ and ‘wheeze in the last year’ in the children. Contrary to findings at 5 years no association between maternal vitamin E intake and asthma outcomes was seen. Longitudinally over the 10 years of the study, higher maternal vitamin D and E intakes during pregnancy were both associated with a decreased likelihood of ‘doctor diagnosed asthma’, ‘active asthma’ and ‘wheeze in the last year’ in the children. In conclusion, reduced maternal vitamin D and E intakes during pregnancy are associated with an increased likelihood of childhood asthma during the first ten years of life. Vitamin E appears to be associated with early asthma and wheeze possibly reflecting a role in affecting early airway remodelling processes. Associations with vitamin D were seen consistently over different time-points, possibly having its effect in an immunomodulatory fashion. Intervention trials are required to ascertain if intervention during pregnancy actually reduces childhood asthma rates.