Colorectal Chemoprevention with Calcium and Vitamin D

描述（由申请方提供）：上呼吸道感染（URTI）、流感样疾病（ILI）和急性胃肠道感染（AGI）在美国很常见，并与显著的发病率和经济负担相关。越来越多的证据表明，维生素D可能在免疫功能中发挥重要作用;流行病学和临床研究证明，维生素D水平较低与几种传染病（特别是呼吸道传染病）风险增加之间存在关联。我们建议通过在我们正在进行的随机、安慰剂对照双盲试验中增加适当的症状监测来评估补充维生素D对常见呼吸道和胃肠道感染的发生率和持续时间的影响，该试验旨在测试补充维生素D（每日1000 IU）或钙（每日1200 mg）预防结直肠腺瘤的有效性。该试验已完成招募，将有超过1000名受试者仍在接受研究治疗，并可能在至少一个冬季进行症状监测评估。受试者很好地遵守了研究方案，并且该试验已经收集了关于生活方式，25-（OH）维生素D水平和主要医疗事件的广泛数据。在本文拟定的研究中，将招募来自母试验的受试者，以完成关于URTI、ILI和AGI的每月症状日记。将每天完成纸质或网络形式的日记，并每月返回研究协调中心。将指导受试者记录长达12个月的呼吸道和胃肠道症状。使用URTI、ILI和AGI的预定义定义，我们将采用每种疾病的发作次数和受疾病影响的总天数作为终点。主要分析将侧重于URTI;探索性分析将针对ILI和AGI。我们预计将能够招募至少812名受试者参与这项工作，其中一半以上将接受为期一年的监测。我们估计，我们将有超过80%的把握度来检测URTI发病率降低20%或更多，甚至有更大的把握度来评估这些感染对受影响天数的影响。公共卫生相关性：感冒、流感和急性胃肠道感染在美国很常见，并且与显著的健康和经济负担相关。越来越多的证据表明，维生素D对免疫功能很重要，较高的维生素D水平可以预防这些疾病。在这里提出的研究中，我们将评估补充维生素D的能力，以减少发展这些感染性疾病的风险。

DESCRIPTION (provided by applicant): Upper respiratory tract infection (URTI), influenza like illness (ILI) and acute gastrointestinal infection (AGI) are common in the U.S. and are associated with significant morbidity and economic burden. Accumulating evidence indicates that vitamin D may play an important role in immune function; epidemiologic and clinical studies have documented an association between lower vitamin D levels and increased risk of several infectious diseases, particularly those of the respiratory tract. We propose to evaluate the effect of supplementation with vitamin D on the incidence and duration of common respiratory and gastrointestinal infections by adding appropriate symptom surveillance to our ongoing randomized, placebo-controlled double blind trial testing the efficacy of supplementation with vitamin D (1000Iu daily) or calcium (1200 mg daily) for the prevention of colorectal adenomas. The trial has completed recruitment, and will have over 1000 subjects still on study treatment and potentially evaluable for symptom surveillance over at least one winter season. Subjects have complied well with the study protocol, and the trial has extensive data already collected regarding lifestyle, 25-(OH) vitamin D levels, and major medical events. In the research proposed here, subjects from the parent trial will be recruited to complete monthly symptom diaries regarding URTI, ILI and AGI. The diaries, either in paper form or web- based, will be will be completed daily and returned monthly to the Study Coordinating Center. Subjects will be instructed to record respiratory and gastrointestinal symptoms for up to 12 months. Using pre-defined definitions of URTI, ILI and AGI, we will adopt as endpoints the number of episodes of each type of illness and the total number of days of affected by the illness. Primary analyses will focus on URTI; exploratory analyses will address ILI and AGI. We project that will be able to recruit at least 812 subjects into this effort, more than half of whom will be monitored for a full year. We estimate we will have greater than 80% power to detect a reduction of 20% or more in the incidence of URTI and even greater power to assess effects on number of days affected by these infections. PUBLIC HEALTH RELEVANCE: Colds, influenza and acute gastrointestinal infections are common occurrences in the United States, and are associated with a significant health and economic burden. Accumulating evidence indicates that vitamin D is important for immune functioning and that higher vitamin D levels may protect against these illnesses. In the study proposed here, we will evaluate the ability of supplemental vitamin D to reduce the risk of developing those infectious disorders.