Estimation of the Dietary Requirement for Vitamin D in Ethnic Groups: a Double-blind, Randomised, Dose-response Trial
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 114
- 试验地点
- 2
- 主要终点
- Concentration of serum 25(OH)D (nmol/L)
研究概览
简要总结
The aim of this study is to perform a double-blind, randomised, dose-response trial of vitamin D3 supplementation in United Kingdom (UK)-dwelling adults of white European, South Asian, and black African/Caribbean ethnicity to investigate the distribution of dietary intakes needed to maintain adequate vitamin D status in winter, as indicated by serum 25(OH)D concentrations at ranges of >25 to 50 nmol/L. In addition, this study will investigate the effect of vitamin D3 supplementation on immune health, muscular strength, and overall health.
详细描述
The aim of this study is to perform a double-blind, randomised, dose-response trial of vitamin D3 supplementation in United Kingdom (UK)-dwelling adults of white European, South Asian, and black African/Caribbean ethnicity to investigate the distribution of dietary intakes needed to maintain adequate vitamin D status in winter, as indicated by serum 25(OH)D concentrations at ranges of >25 to 50 nmol/L. In addition, this study will investigate the effect of vitamin D3 supplementation on immune health, muscular strength, and overall health. Recruited participants will be randomised to take 400, 1000, or 2000 IU for 12 weeks. Fasting blood samples collected at baseline and 12 weeks will measure biochemical markers of vitamin D status (serum 25(OH)D, calcium, parathyroid hormone, albumin), lipid profile, ferritin, micronutrient status, and immune and inflammatory biomarkers. Muscular strength will be measured using sit-to-stand and grip strength tests. Questionnaires, food diaries, and dosimeters will be used to gather data on lifestyle, physical activity, dietary intake, and sun exposure.
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
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •British white European, black African/Caribbean, or South Asian (self-reported)
- •Living in England for >2 months
- •Aged >18 years
- •No significant health issues
- •English or Urdu speaker
排除标准
- •Medical condition or history which might impact study measurements (e.g., ischaemic heart disease, type 1 and type 2 diabetes, thyroid disease, osteoporosis, haematological disease, malignancy)
- •Medications known to affect vitamin D metabolism (i.e., hormone replacement therapy, anti-oestrogens treatment, antiepileptic drugs, and breast cancer treatment)
- •Pregnant or planning pregnancy during the study period
- •Regular use of sun beds
- •Having a sun holiday one month prior to commencing study or plans for a sun holiday within the study period. A sun holiday is generally defined as a holiday in a sunny resort outside of the UK. The researchers will assess this on a case-by-case basis depending on the time of year and expected weather conditions
- •Reported participation in another clinical trial occurring simultaneously
- •Previous intolerance or allergic reaction to vitamin D
结局指标
主要结局
Concentration of serum 25(OH)D (nmol/L)
时间窗: Baseline and 12 weeks
A blood sample will be analysed using liquid chromatography tandem mass spectroscopy (LC-MS). Dose-response change in serum 25(OH)D will be measured in nmol/L.
次要结局
- Anthropometric measurements - weight (kg)(Baseline and 12 weeks)
- Anthropometric measurements - height (m)(Baseline and 12 weeks)
- Blood analytes - micronutrient status(Baseline and 12 weeks)
- Blood analytes - lipid profile (mg/dL)(Baseline and 12 weeks)
- Physical activity questionnaire(Baseline)
- Ultraviolet B radiation (UVB) sun exposure(Baseline and 12 weeks)
- Anthropometric measurements - height (cm)(Baseline and 12 weeks)
- Anthropometric measurements - waist circumference (cm)(Baseline and 12 weeks)
- Number of participants with Acute Respiratory Tract Infections (ARTIs)(12 weeks)
- Muscular strength using a handgrip strength test (kg)(Baseline and 12 weeks)
- Concentration of serum calcium (nmol/L)(Baseline and 12 weeks)
- Concentration of serum albumin (g/L)(Baseline and 12 weeks)
- Complete blood count(Baseline and 12 weeks)
- Change in immune parameters(Baseline and 12 weeks)
- Vitamin D consumption from diet(Baseline and 12 weeks)
- Anthropometric measurements - hip circumference (cm)(Baseline and 12 weeks)
- Concentration of plasma parathyroid hormone (PTH) (pg/mL)(Baseline and 12 weeks)
- Concentration of C-Reactive Protein (CRP) (mg/L)(Baseline and 12 weeks)
- Muscular strength and endurance using a sit-to-stand test(Baseline and 12 weeks)
- Sun exposure behaviour questionnaire(Baseline)
- Lifestyle questionnaire(Baseline)