A Double-Blind, Randomized, Control Study to Examine the Effects of Vitamin D Fortification on Vitamin D Metabolite Profiles and Status in Vitamin D Insufficient Individuals.
试验速览
- 阶段
- 1 期
- 状态
- 撤回
- 试验地点
- 2
- 主要终点
- Plasma/Serum and Urine Vitamin D Metabolite Profiles of Vitamin D Sufficient and Insufficient Individuals
研究概览
简要总结
This is a cross-sectional study designed to compare plasma/serum and urine vitamin D metabolite profiles of vitamin D sufficient and insufficient individuals.
There are two phases of this study.
Phase 1 - Consented study participants will attend a screening visit and provide a fasting blood and urine sample. Those individuals who are vitamin D insufficient based on serum 25(OH)D concentrations will be invited to participate in Phase II
Phase II - is a double-blind, randomized, control study designed to examine vitamin D status in vitamin D insufficient individuals consuming a water-soluble form of vitamin D3. Eligible participants will be asked to consume one of three beverages: i) rooibos iced-tea (control); ii) rooibos iced-tea fortified with 1000 IU of water-soluble vitamin D3; or iii) rooibos iced-tea fortified with 1000 IU of water-soluble vitamin D3 and 360 mg calcium at 240 mL of iced-tea consumed daily for 6 weeks. Participants will attend 6 weekly visits following baseline and provide a fasting blood sample for assessment of serum 25(OH)D concentrations.
Objectives: 1) To investigate plasma/serum and urine vitamin D metabolite profiles in vitamin D sufficient and insufficient individuals; and 2) To determine the effects of vitamin D3 fortification on serum 25-dihydroxy-vitamin D [25(OH)D] concentrations, markers of vitamin D and calcium metabolism, and vitamin D metabolite profile in plasma/serum and urine of vitamin D insufficient individuals.
详细描述
Health individuals from the general public will be recruited into this cross-sectional study designed to compare plasma/serum and urine vitamin D metabolite profiles of those identified as vitamin D sufficient and insufficient individuals.
There are two objectives:
Objective 1: To investigate plasma/serum and urine vitamin D metabolite profiles in vitamin D sufficient and insufficient individuals; N=20 and will consist of 10 individuals identified as vitamin D insufficient and 10 individuals identified as vitamin D deficient individuals.
Objective 2: To determine the effects of vitamin D3 fortification on serum 25-dihydroxy-vitamin D [25(OH)D] concentrations, markers of vitamin D and calcium metabolism, and vitamin D metabolite profile in plasma/serum and urine of vitamin D insufficient individuals. N=45.
To achieve the objectives, the study will be conducted in two phases:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 19 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •A. Inclusion Criteria for Objective 1 (Part One):
- •Adult volunteers, male or female, between 19 and 50 years of age;
- •Body mass index (BMI) ≥20 and ≤30 kg/m2 (normal to overweight);
- •Must be on a stable regime for the past three months, if taking vitamin and mineral/dietary/herbal supplements; and
- •Willing to provide informed consent.
- •B. Inclusion Criteria for Objective 2 (Part Two):
- •Adult volunteers, male or female, between 19 and 50 years of age;
- •Body mass index (BMI) ≥20 and ≤30 kg/m2 (normal to overweight);
- •Must be on a stable regime for the past three months, if taking vitamin and mineral/dietary/herbal supplements;
- •Vitamin D insufficient (serum 25(OH)D concentrations ≥30 and ≤75 nmol/L);
- •Willing to comply with protocol requirements; and
- •Willing to provide informed consent.
排除标准
- •Take a vitamin D or calcium supplement within the last three months before the start date of the study, or during the study;
- •History of vitamin D deficiency (serum 25(OH)D concentration <30 nmol/L);
- •History of hypocalcaemia;
- •Presence of a clinically diagnosed disease affecting the circulatory, respiratory, immune, skeletal, urinary, muscular, endocrine, digestive, nervous or reproductive system that requires medical treatment;
- •Taking any medication (with the exception of birth control);
- •Daily consumption of more than three servings of dairy products;
- •Undergone significant sun exposure one month before start date of the study;
- •Use or have used a tanning booth one month before start date of the study, or during the study;
- •Plan to travel to a sunny climate during the study;
- •Currently smoking or have smoked within the last six months before start date of the study, or during the study;
- •Have allergies to tea products;
- •Pregnant or lactating; and
- •Consume excessive alcohol (>10 drinks/week for women, >15 drinks/week for men).
结局指标
主要结局
Plasma/Serum and Urine Vitamin D Metabolite Profiles of Vitamin D Sufficient and Insufficient Individuals
时间窗: Screening Visit (Day 0) - Phase 1
To investigate plasma/serum and urine vitamin D metabolite profiles in vitamin D sufficient and insufficient individuals.
The Effects of Vitamin D Fortification on Serum 25(OH)D in Vitamin D Insufficient Individuals.
时间窗: 6 Weeks (Phase II)
To determine the effects of 6 weeks of vitamin D3 fortification on serum 25-dihydroxy-vitamin D \[25(OH)D\] concentrations of vitamin D insufficient individuals.
次要结局
- The Effects of vitamin D3 Fortification on calcium metabolism of Vitamin D Insufficient Individuals.(6 Weeks (Phase II))
- The Effects of Vitamin D3 Fortification on Vitamin D Metabolite Profile of Vitamin D Insufficient Individuals.(6 Weeks (Phase II))
- The Effects of Vitamin D3 Fortification on markers of vitamin D of vitamin D insufficient individuals(6 Weeks (Phase II))