Vitamins and minerals
Vitamin D insufficiency and deficiency have been associated with IgE
sensitization157 and
FA in some studies158but not others.159There is little evidence from interventional studies of vitamin D
supplementation for primary allergy
prevention160-163 as
reviewed by Yepes-Nunez, et
al.164 The lack of
evidence about the role of vitamin D in FA risk is in part related to
the multiple factors influencing vitamin D levels that need to be
accounted for when designing studies. These factors include sun
exposure, country and latitude of residence, migratory status, skin
colour, ethnicity, age, diet, vitamin D supplementation (timing,
formulation and dose), genetic polymorphisms affecting metabolism,
epigenetic changes contributing to vitamin D levels, vitamin D binding
protein, interaction with disease-associated genetic polymorphisms
(e.g., ORMDL3), definition of vitamin D insufficiency/deficiency, and
time-points to assess levels (longitudinal versus
cross-sectional)165.
One systematic review indicated that intake of beta-carotene, vitamin E,
zinc, calcium, magnesium, and copper during pregnancy might be
protective of offspring
AD146. This review
also summarized a small number of papers indicating that copper and
vitamin C intake during pregnancy may reduce the risk of offspring FA.
In contrast, vitamin D intake was associated with an increased risk of
offspring FA. The amount of vitamins and minerals taken in these studies
did not align with healthy eating guidance, and the results should be
interpreted with
caution146.
Results from RCTs have been summarized in several guideline papers and
systematic reviews, with or without meta-analysis, to guide families.
Results from these meta-analyses largely support current recommendations
from the American Academy of Pediatrics
(AAP),166EAACI,17 and the
consensus statement from the 3 North American allergy
societies.16 All
refrain from making recommendations on omega-3 fatty acids, vitamins,
minerals, or pre-/pro-/syn-biotics for allergy prevention.