Randomized Controlled Trial to Explore the Inter-relationship Between Vitamin D Requirements and Calcium Intake
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 125
- 试验地点
- 1
- 主要终点
- Response of serum 25(OH)D concentration over winter in subjects stratified by calcium intake
研究概览
简要总结
This winter-based placebo-controlled, single-dose vitamin D randomized controlled trial (RCT) aims to examine the impact of various levels of habitual calcium intake on dietary vitamin D requirements in older adults stratified by calcium intake. This will provide new data on the impact of different levels of calcium intake, ranging from low/moderate to high, on winter serum 25(OH)D levels, and their utilization and catabolism in adults.
详细描述
The aim of this study is to perform a randomised controlled vitamin D3 intervention study in apparently healthy, free-living adults (aged 50+ y) to investigate whether different levels of habitual calcium intake, ranging from low-moderate to high, influence serum 25(OH)D concentrations and indices of vitamin D activation and catabolism during winter, when vitamin D intake is adequate versus inadequate.
This research will provide new data and scientific understanding in relation to the impact of different levels of dietary calcium intake on vitamin D requirements in the older adult population. As such, this new data will inform dietary reference values for vitamin D.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 50 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Consenting white men and women aged ≥ 50 y
排除标准
- •Unwilling to discontinue consumption of vitamin D-containing supplements 4 wks before the initiation of the study and throughout the study.
- •Planning to take a winter vacation (during the course of the 15-wk intervention) to a location at which either the altitude or the latitude was predicted to result in significant cutaneous vitamin D synthesis from solar radiation (e.g., a winter sun coastal resort or a mountain ski resort)
- •Use of tanning facilities of any type.
- •Pregnancy or planning to become pregnant during the study
- •A severe medical illness,
- •hypercalcaemia,
- •Known intestinal malabsorption syndrome,
- •Excessive alcohol use,
- •Taking medications known to interfere with vitamin D metabolism
结局指标
主要结局
Response of serum 25(OH)D concentration over winter in subjects stratified by calcium intake
时间窗: 0, 8, 15 weeks
次要结局
- Serum 24,25(OH)2D(0 and 15 weeks)
- Serum 1,25(OH)2D(0 and 15 weeks)
- Serum free 25(OH)D(0 and 15 weeks)
- Serum albumin-adjusted calcium(0, 8, 15 weeks)
- serum parathyroid hormone(0, 8, 15 weeks)
- Serum vitamin D binding protein(0 and 15 weeks)
研究者
Kevin D. Cashman
Professor of Food and Health
University College Cork