Childhood asthma is the most common chronic disease of childhood in the United States and globally. Maternal asthma is a major risk factor in the development of childhood asthma and wheezing. The vitamin D (VD) status in pregnancy has emerged as a modifiable factor influencing these outcomes. The combined effects of maternal asthma status and prenatal VD status across pregnancy have not been assessed to date.
Lu and colleagues examined the combined effects of prenatal vitamin D sufficiency (25-hydroxyvitamin D = 30 ng/mL) and maternal asthma status on the development of childhood asthma or recurrent wheeze by age 3 years.
High Risk of Asthma
The study included 806 mother-offspring pairs from the Vitamin D Antenatal Asthma Reduction Trial (vitamin DAART), a randomized double-blinded placebo-controlled trial of vitamin D supplementation in pregnant women at high risk of offspring asthma due to a maternal or paternal history of asthma or atopy.
Vitamin D sufficiency status was examined in early (10-18 weeks of gestation) and late pregnancy (32-38 weeks of gestation).
Among mothers with asthma, vitamin D sufficiency in either early or late pregnancy was associated with an almost halved risk of childhood asthma or recurrent wheeze by age 3 years compared to vitamin D insufficiency in both early and late pregnancy.
Advantages of Vitamin D
Vitamin D sufficiency in both early and late pregnancy was associated with a further reduction of the risk to two-thirds. This protective trend was reiterated in the progression of childhood asthma or recurrent wheeze from age 3 years to active asthma at age 6 years, regardless of maternal asthma status.
Based on these findings, the authors suggest a protective role for prenatal vitamin D sufficiency throughout pregnancy on the subsequent development of childhood asthma and recurrent wheeze outcomes, particularly in women with asthma, who are at a higher baseline risk of offspring asthma.
Further studies may shed light on the underlying mechanisms of the effects of prenatal vitamin D and its optimal levels in the prevention of offspring asthma.
Source: Lu M, et al. "Effect of early and late prenatal vitamin D and maternal asthma status on offspring asthma or recurrent wheeze." The Journal of Allergy and Clinical Immunology. 18 August 2020.