美国戈利萨诺儿童医院Augusto A. Litonjua研究小组近日取得一项新成果。他们对产前补充维生素D是否能降低儿童哮喘的发生率进行了后续试验。 2020年2月6日，国际知名学术期刊《新英格兰医学杂志》发表了这一成果。

研究组之前报道了一项产前补充维生素D预防幼儿哮喘和复发性喘鸣的试验结果，表明产前补充维生素D在幼儿3岁时具有保护作用。

在这项后续研究中，研究组想确定，考虑到母体内25-羟基维生素D的水平，在怀孕期间每天服用4400IU维生素D3的母亲所生的孩子（维生素D组）在幼儿6岁时哮喘和复发性喘鸣的发生率是否会低于孕期每天服用400IU维生素D的母亲所生的孩子（对照组）。

在意向治疗分析或根据母体孕期25-羟基维生素D水平的分层分析中，补充维生素D对哮喘和复发性喘鸣均无影响。产前补充维生素D对儿童的包括肺活量指数在内的大多数临床指标均无影响。

总之，仅在产前补充维生素D并不会降低有哮喘风险的儿童在6岁时哮喘和复发性喘鸣的发病率。

附：英文原文

Title: Six-Year Follow-up of a Trial of Antenatal Vitamin D for Asthma Reduction

Author: Augusto A. Litonjua, M.D., M.P.H.,, Vincent J. Carey, Ph.D.,, Nancy Laranjo, B.A.,, Benjamin J. Stubbs, B.A.,, Hooman Mirzakhani, M.D., Ph.D.,, George T. O’Connor, M.D.,, Megan Sandel, M.D., M.P.H.,, Avraham Beigelman, M.D.,, Leonard B. Bacharier, M.D.,, Robert S. Zeiger, M.D., Ph.D.,, Michael Schatz, M.D.,, Bruce W. Hollis, Ph.D.,, and Scott T. Weiss, M.D.

Issue&Volume: 2020-02-05

Abstract:

Background
We previously reported the results of a trial of prenatal vitamin D supplementation to prevent asthma and recurrent wheeze in young children, which suggested that supplementation provided a protective effect at the age of 3 years. We followed the children through the age of 6 years to determine the course of asthma and recurrent wheeze.

Methods
In this follow-up study, investigators and participants remained unaware of the treatment assignments through the children’s sixth birthday. We aimed to determine whether, when maternal levels of 25-hydroxyvitamin D were taken into account, children born to mothers who had received 4400 IU of vitamin D3 per day during pregnancy (vitamin D group) would have a lower incidence of asthma and recurrent wheeze at the age of 6 years than would those born to mothers who had received 400 IU of vitamin D3 per day (control group). Time-to-event methods were used to compare the treatment groups with respect to time to the onset of asthma or recurrent wheeze. Multivariate methods were used to compare longitudinal measures of lung function between the treatment groups.

Results
There was no effect of maternal vitamin D supplementation on asthma and recurrent wheeze in either an intention-to-treat analysis or an analysis with stratification according to the maternal 25-hydroxyvitamin D level during pregnancy. There was no effect of prenatal vitamin D supplementation on most of the prespecified secondary outcomes. We found no effects of prenatal supplementation on spirometric indexes. Although there was a very small effect on airway resistance as measured by impulse oscillometry, this finding was of uncertain significance.

Conclusions
Vitamin D supplementation during the prenatal period alone did not influence the 6-year incidence of asthma and recurrent wheeze among children who were at risk for asthma. (Funded by the National Heart, Lung, and Blood Institute; VDAART ClinicalTrials.gov number, NCT00920621.)

DOI: 10.1056/NEJMoa1906137

Source: https://www.nejm.org/doi/full/10.1056/NEJMoa1906137