Evaluation of Calcium, Vitamin D, Magnesium, and Zinc Absorption in Healthy Children 4 to 8 Years of Age
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 60
- 试验地点
- 2
- 主要终点
- To evaluate the effects of supplemental vitamin D in enhancing calcium absorption in healthy children 4 to 8 yrs of age.
研究概览
简要总结
The goal of our research is to provide data to enhance the development of nutritional guidelines, especially as related to mineral nutrition, in children. Using human experimentation, we are studying methods of delivering the key minerals of calcium, zinc and iron in the diet so as to optimize health outcomes. We will conduct a controlled trial of vitamin D supplementation to assess the effects of vitamin D status on calcium absorption in small children. We will evaluate the effects of differing intakes of zinc on zinc and copper absorption. These studies will utilize stable isotope techniques so as to provide accurate, practically applicable information which may be obtained from the study populations in a safe manner. These data will have global application and provide a strong basis for evidence-based nutritional recommendations to be developed.
Objective #1: To evaluate the effects of supplemental vitamin D in enhancing calcium absorption in healthy children 4 to 8 yrs of age.
Objective #2: Assess the absorption of magnesium and zinc in healthy children 4 to 8 yrs of age.
详细描述
We plan to stratify subjects for randomization to either vitamin D supplements or placebo by serum 25-hydroxyvitamin D (25 OHD) into three groups: 0-20 ng/mL, 20-32 ng/mL, and >32 ng/mL.
There is no group assignment or randomization for the magnesium and zinc aspects of the study.
SCREENING VISIT: At the time of enrollment, subjects and their families will be asked to come to the General Clinical Research Center (GCRC) of Texas Children's Hospital for a screening visit. Prior to this visit, demographics from the parent/guardian will be recorded including the child's approximate height and weight, and the study dietitian will obtain two 24-hour dietary recalls from the parent to determine calcium intake for enrollment. During this screening visit, informed written consent will be obtained, a medical history taken, and a physical examination performed.
The study dietitian will instruct the parent/guardian and child on the use of a food scale to weigh and record dietary intake for a 3-day period (ie, 3-day weighed diet record). The 3-day weighed diet record will begin the following day. This method has been shown to provide the best estimate of dietary intakes in children (Crawford PB et al, J Am Diet Assoc. 1994; 94:626-630; Fisher JO et al, Am J Clin Nutr. 2008; 88:407-415). Upon analysis of their child's intake, parents will be instructed to maintain a similar nutrient intake throughout the study. Compliance will be monitored via 3-day weighed home diet records timed with their other study visits. If analysis shows that the child's intake has significantly changed (± 20% of a nutrient), the parent will be counseled by the study dietitian on readjusting the child's intake back to the usual level determined at baseline.
In addition, the study dietitian will prepare sample menus based on the child's food preferences and dietary intake levels and provide them to the parent. Parents can use the sample menus to assist them in maintaining the child's usual mineral intake.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 4 Years 至 8 Years（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Delivery at > or = 35.0 weeks gestation with birth weight > or = 2.5 kg
- •BMI: 10th - 90th percentile for age and gender
- •Ages 4.0 to 8.9 years
- •Ethnic distribution of greater Houston area
- •Usual calcium intake 600-1200 mg/d based on two 24-hour dietary recalls by phone
- •Any regularly taken (daily) vitamins and minerals must be stopped at least 1 month before starting the study
排除标准
- •History of any chronic illness.
- •Regularly taken (daily) medications (except seasonal allergies).
- •Avoidance of dairy products or meat in the diet.
结局指标
主要结局
To evaluate the effects of supplemental vitamin D in enhancing calcium absorption in healthy children 4 to 8 yrs of age.
时间窗: End of the study
次要结局
- Assess the absorption of magnesium and zinc in healthy children 4 to 8 yrs of age.(End of the study)
研究者
Steve Abrams
Professor
Baylor College of Medicine