Wheezing in Black Preterm Infants: Impact of Vitamin D Supplementation Strategy

描述（由申请人提供）：黑人婴儿面临着美国最高的早产率（18%），早产相关喘息疾病的发病率很高，并且往往维生素D水平较低。这项[比较有效性]研究的目的是确定一种维生素。补充维生素D的策略，最大限度地减少婴儿期反复喘息。长期以来，维生素被认为对骨骼健康很重要，越来越多的证据表明维生素。D可能在许多器官系统的调节和发育中起作用。D通路调节肺部炎症并影响支气管平滑肌的形态发生、结构和细胞生长和存活。Vit. D暴露有可能使细胞因子表达从Th 1（过敏性较低）向Th 2（过敏性较高）表型倾斜。由于他们的发育不成熟，早产儿可能特别容易受到维生素的任何积极或消极影响。补充维生素D对肺、呼吸道和免疫系统的影响。我们的初步数据，并得到文献的支持，表明过于积极的维生素。补充维生素D可能会无意中增加黑人早产儿的喘息，但不会增加白色早产儿的喘息。从理论上讲，维生素D缺乏也可能通过易受呼吸道病原体感染而增加喘息。这项研究是一项随机临床试验，比较了两种不同的肠内维生素D补充策略对300例胎龄为300/7-366/7周早产的黑人婴儿在婴儿期反复喘息的影响。D要求也不是最佳的维生素。D血清水平已确定。我们将测试两种策略：（I）持续补充，直到6个月。年龄调整为早产，和（II）停止补充时，达到最低膳食摄入量200 IU/天。具体目的是描述每种策略对（目的1）复发性喘息和（目的2）[过敏性致敏]和特应性的影响。我们将（目的3）探讨维生素。血清维生素D水平与反复喘息。我们假设策略II通过最大限度地减少反复喘息、[过敏性致敏]和整体医疗保健利用，在促进肺部健康方面更有效，并足以预防临床维生素E。D缺乏症。我们还假设最佳维生素。D血清水平将低于其他人群的标准。理论联系：维生素。D状态和健康。

DESCRIPTION (provided by applicant): Black infants face the highest rates of prematurity in the U.S. (18%), have high rates of prematurity-associated wheezing illnesses, and tend to have lower vitamin D levels. The goal of this [comparative effectiveness] study is to identify a vit. D supplementation strategy that minimizes recurrent wheezing in infancy. Long recognized as important for bone health, a growing body of evidence suggests that vit. D may play a role in the regulation and development of many organ systems. The D pathway regulates lung inflammation and impacts morphogenesis, structure, and cell growth and survival in bronchial smooth muscle. Vit. D exposure has the potential to skew cytokine expression from a Th1 (less allergic) to a Th2 (more allergic) phenotype. Due to their developmental immaturity, preterm infants may be particularly vulnerable to any positive or negative effects of vit. D supplementation on the lung, airway, and immune system. Our preliminary data, supported by the literature, suggests that overly aggressive vit. D supplementation may inadvertently increase wheezing in infancy in black, but not white, preterm infants; however, vit. D deficiency could theoretically also increase wheezing via vulnerability to respiratory pathogens. The proposed study is a randomized clinical trial comparing the effect of two different enteral vitamin D supplementation strategies on recurrent wheezing in infancy in 300 black infants born preterm at 300/7-366/7 wks gestational age, a population for whom neither vit. D requirements nor optimal vit. D serum levels have been established. We will test two strategies: (I) sustained supplementation until 6 mo. of age adjusted for prematurity, and (II) cessation of supplementation when a minimum dietary intake of 200 IU/day is reached. The specific aims are to characterize the effect of each strategy on (aim 1) recurrent wheezing and (aim 2) [allergic sensitization] and atopy. We will (aim 3) explore the relationship between vit. D serum levels and recurrent wheezing. We hypothesize that strategy II will be more effective in promoting pulmonary health by minimizing recurrent wheezing, [allergic sensitization], and overall healthcare utilization, and will be sufficient to prevent clinical vit. D deficiency. We also hypothesize that optimal vit. D serum levels will be lower than the norms for other populations. Theoretical Association: Vit. D Status and Health.