Association between Maternal Vitamin D Intake and Infant Allergies: The Japan Environment and Children's Study

Area of Science:

• Perinatal nutrition and immunology
• Pediatric allergy and immunology
• Public health and epidemiology

Background:

• Maternal nutrition influences offspring health.
• Conflicting evidence exists regarding maternal vitamin D and offspring allergies.
• Optimal maternal vitamin D levels for preventing childhood allergies are unclear.

Purpose of the Study:

• To investigate the association between maternal vitamin D intake during pregnancy and the development of allergic diseases in offspring at one year of age.
• To analyze data from a large-scale nationwide birth cohort study in Japan.
• To clarify the role of maternal vitamin D in the etiology of childhood allergic conditions.

Main Methods:

• Utilized data from the Japan Environment and Children's Study (JECS) cohort.
• Analyzed dietary information on maternal vitamin D intake via food frequency questionnaires.
• Assessed parent-reported physician-diagnosed allergic diseases (asthma, food allergy, atopic dermatitis) in offspring at age one.
• Included 82,592 mother-offspring pairs in the final analysis after data cleaning.

Main Results:

• The mean maternal vitamin D intake (4.7 μg/d) was below the Japanese recommendation (7 μg/d).
• While some quintiles showed increased odds for asthma and food allergies, overall associations were not clear.
• No definitive link was established between maternal vitamin D intake and the development of common allergic diseases in one-year-old children.

Conclusions:

• This large nationwide study found no clear association between maternal vitamin D intake and offspring allergic diseases at age one.
• The potential protective effects of vitamin D supplementation in pregnancy for preventing childhood allergies require further investigation.
• Current findings suggest that maternal vitamin D intake alone may not be a significant determinant of early-onset allergic diseases in offspring.