Vitamin D is critical for immune regulation and respiratory health, yet its supplementation during pregnancy shows inconsistent results in preventing respiratory and allergy-related outcomes in children. This systematic review and meta-analysis aim to evaluate the impact of maternal vitamin D supplementation on respiratory tract infections (RTI), asthma, wheezing, eczema, and allergy in offspring.
MethodsA comprehensive search was performed in PubMed, Embase, Web of Science, Cochrane Library up to December 2024. We included randomized controlled trials (RCTs) examining the effects of prenatal vitamin D supplementation on respiratory and allergy-related outcomes in children. The GRADE approach was applied to assess the quality of evidence, and the Cochrane risk-of-bias tool was used to evaluate study quality.
ResultsSeven RCTs were included (3958 mother-infant pairs). Prenatal vitamin D supplementation did not significantly reduce RTI in children compared to controls (RR = 1.018, 95% CI: 0.965 to 1.074, p = 0.514). Similarly, no significant effects were observed for asthma (RR = 0.395, 95% CI: 0.670 to 1.308, p = 0.699), wheezing (RR = 0.824, 95% CI: 0.826 to 1.089, p = 0.174), eczema (RR = 0.954, 95% CI: 0.826 to 1.102, p = 0.522), allergic conditions (RR = 0.938, 95% CI: 0.841 to 1.047, p = 0.255), or IgE positivity (RR = 0.942, 95% CI: 0.736 to 1.207, p = 0.639). Subgroup analyses showed no significant effect modification based on control group supplementation or follow-up duration.
ConclusionThere is moderate-quality evidence suggesting that prenatal vitamin D supplementation has minimal or no significant effect on reducing respiratory tract infections and allergy-related outcomes in children.
KeywordsVitamin D
Respiratory tract infections
Allergic conditions
Pregnancy outcomes
Systematic review
© 2025 The Author(s). Published by Elsevier Inc. on behalf of World Allergy Organization.
Comments (0)