Taking vitamin D during pregnancy is linked to a significant reduction in the likelihood of asthma in newborns. The findings were reported by researchers in a study published in the Journal of Allergy and Clinical Immunology.
Vitamin D is produced in the body when skin is exposed to sunlight and is also obtained from certain foods. In the recent paper, researchers examined data from multiple publications that explored the connection between childhood asthma and vitamin D status. Observational studies have suggested that higher vitamin D levels during pregnancy may offer protection against asthma, while clinical trials where expectant mothers received vitamin D supplements have yielded mixed results.
The analysis conducted by the VDAART investigators reported no clear association between vitamin D intake during pregnancy and asthma risk overall. The authors argued that earlier findings could be explained by not accounting for baseline vitamin D levels before supplementation. In a reanalysis that included baseline status, a daily intake of 4,400 international units during pregnancy, during the window of 10 to 18 weeks, appeared to reduce the relative risk of asthma and related breathing symptoms in children by about half. These results aligned with the trends seen in observational studies and emphasized the potential role of starting vitamin D status in interpreting outcomes.
Vitamin D deficiency is common, particularly among pregnant individuals who do not take supplements. Based on the reanalysis, the researchers recommended that pregnant people consider maintaining a daily intake of 4,400 international units of vitamin D3 from early pregnancy onward, while underscoring the importance of discussing any supplementation plan with a healthcare professional.
As with any supplement or medication, a prior consultation with a clinician is advised to ensure safety and appropriateness for individual health needs.
Further context from the broader literature indicates that vitamin D remains a focus of ongoing research about its role in fetal development and immune function, with consensus continuing to evolve as new data emerge.