PURPOSE OF THE STUDY.
Previous studies have provided mixed results regarding a relationship of intake of dairy products with allergic disorders. This study examined the association between maternal consumption of dairy products, calcium, and vitamin D during pregnancy and risk of wheeze and eczema in Japanese children at 16 to 24 months of age.
A total of 763 mother-child pairs in the Osaka Maternal and Child Health Study (OMCHS) were included.
The OMCHS is a prospective cohort study. Participants mailed each of 3 questionnaires to the data center. The first survey was performed on pregnant women between the 5th and 39th weeks of gestation, and the second and third surveys were collected from 2 to 9 and 16 to 24 months after delivery, respectively. Symptoms of wheeze and eczema were based on the criteria of the International Study of Asthma and Allergies in Childhood.
Higher maternal intake of total dairy products, milk, cheese, and calcium during pregnancy was significantly related to a decreased risk of infantile wheeze but not eczema (adjusted odds ratios [ORs] between extreme quartiles were 0.45 [95% confidence interval (CI): 0.25–0.79], 0.5 [95% CI: 0.28–0.87], 0.51 [95% CI: 0.31–0.85], and 0.57 [95% CI: 0.32–0.99], respectively). Children whose mother had consumed ≥4.3 μg/day of vitamin D, using a cutoff point at the 25th percentile, had a significantly reduced risk of wheeze and eczema (adjusted ORs were 0.64 [95% CI: 0.43–0.97] and 0.63 [95% CI: 0.41–0.98], respectively). However, the inverse associations between maternal intake of calcium in the highest quartile and ≥4.3 μg/day of vitamin D and infantile wheeze were not statistically significant after further control for maternal intake of docosahexaenoic acid or vitamin E.
Higher consumption of total dairy product, milk, cheese, calcium, and vitamin D during pregnancy might reduce the risk of infantile wheeze. Also, higher maternal vitamin D intake during pregnancy might be protective against eczema.
The role of vitamin D in atopy and other immune disorders is a hot area of research. The results of this study help to place the importance of diet in pregnancy for atopy in a non-Westernized society. However, the need for long-term follow-up and questionnaire-based definitions for wheeze and eczema were a limitation of this cohort study. Confounders include undisclosed sources of vitamin D and calcium. The relationship between actual vitamin D levels and supplement use during pregnancy is still not conclusive. Additional studies to clarify the multifactorial causes of allergic disorders are desirable, and current randomized double-blind placebo-controlled trials that evaluate vitamin D supplements during pregnancy and wheeze/asthma outcomes are ongoing.
- Copyright © 2011 by the American Academy of Pediatrics